San Antonio Mayor Julian Castro entered the national spotlight with his speech at the Democratic National Convention on Tuesday night.

Castro didn't mince words in criticizing Republican presidential candidate Mitt Romney. He argued that the former Massachusetts governor's policies would "dismantle" the middle class.

"We know that in our free market economy some will prosper more than others. What we don't accept is the idea that some folks won't even get a chance," he said. "And the thing is, Mitt Romney and the Republican party are perfectly comfortable with that America."

The AP reports:

Castro also taunted Romney for his shifting positions on issues like abortion rights, gay marriage and his own push for universal health care as governor of Massachusetts.

"Gov. Romney has undergone an extreme makeover, and it isn't pretty," Castro said.

The Romney campaign shot back at Castro's claim the GOP presidential nominee is insensitive to the middle class.

"Middle class families understand that they are not better off than they were four years ago because President Obama's liberal policies have failed to turn around the economy," spokesman Ryan Williams said.

The San Antonio Mayor was introduced by his twin brother Joaquín Castro, who currently serves in the Texas state legislature.

The AP reports:

The Hispanics with the highest profiles in this year's political conventions, Sen. Marco Rubio of Florida and Mayor Julian Castro of San Antonio, stand as opposites in a cultural and political split that has divided millions of U.S. Latinos for decades.

Republicans chose Rubio, who is Cuban-American, to introduce Mitt Romney at the party's convention last week. Democrats, meeting this week in Charlotte, N.C., picked Castro, who is Mexican-American, as keynote speaker, the role that launched a young Barack Obama to national political prominence.

Although they often are lumped together as Hispanics, Rubio and Castro are emblematic of acute political distinctions between Mexican-Americans, who are the largest Latino group in the U.S., and Cuban-Americans, who are the most politically active. Despite their shared language, these two constituencies have different histories in the United States and are subjected to distinctions in immigration policy that go easier on Cuban immigrants.

Castro told the AP, "Historically, many Cuban-Americans for the last few decades have tended to be a little more conservative. So it's not surprising that you would see Sen. Rubio and the Republican nominee for Senate in Texas, Ted Cruz, running as Republicans." He added, "And I don't begrudge them for that. I think the policies they espouse are wrong, are not the best ones. But, you know, they're doing what they believe. And I applaud them for that."

Watch Castro's speech at the Democratic National Convention above.

Loading Slideshow...
  • President Barack Obama laughs with his wife Michelle and his daughters Malia and Sasha after his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • President Barack Obama waves with his wife Michelle and his daughters Malia and Sasha after his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • Joe Biden, Barack Obama

    Vice President Joe Biden and President Barack Obama wave to the delegates at the conclusion of Presdident Obama's speech at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/J. Scott Applewhite)

  • President Barack Obama waves with his wife Michelle and his daughters Malia and Sasha after his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • President Barack Obama waves with his wife Michelle and his daughters Malia and Sasha after his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • President Barack Obama waves with his wife Michelle and his daughters Malia and Sasha after his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • President Barack Obama waves with his wife Michelle and his daughters Malia and Sasha after his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Charlie Neibergall)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama stands with his family, (L-R) First lady Michelle Obama, Sasha Obama, and Malia Obama during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    US President Barack Obama, First Lady Michelle Obama, daughters Malia (L) and Sasha (C) wave after Obama's acceptance speech at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). AFP PHOTO Stan HONDA (Photo credit should read STAN HONDA/AFP/GettyImages)

  • Barack Obama

    President Barack Obama speaks at the Democratic National Convention in Charlotte, N.C., Thursday, Sept. 6, 2012. (AP Photo/Pablo Martinez Monsivais)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    Supporters listen as US President Barack Obama delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). AFP PHOTO Brendan SMIALOWSKI (Photo credit should read BRENDAN SMIALOWSKI/AFP/GettyImages)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage as he accepts the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Win McNamee/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage as he accepts the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Streeter Lecka/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: (L-R) Marian Robinson, Malia Obama, Sasha Obama, First lady Michelle Obama and Second lady Dr. Jill Biden watch as Democratic presidential candidate, U.S. President Barack Obama speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Scott Olson/Getty Images)

  • From left, Michelle Obama's mother Marian, Malia and Sasha Obama, their mother Michelle and Dr. Jill Biden, wife of Vice President Biden, listen to President Barack Obama at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    US President Barack Obama as he delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). AFP PHOTO Brendan SMIALOWSKI (Photo credit should read BRENDAN SMIALOWSKI/AFP/GettyImages)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    The First family welcomes US President Barack Obama as he delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). From L-R, first row: Mother-in-law Marian Robinson, daughter Malia, daughter Sasha, First Lady Michelle Obama, Second Lady Dr. Jill Biden and Mrs.Obama's brother Craig Robinson (3rd R, second row). AFP PHOTO Brendan SMIALOWSKI (Photo credit should read BRENDAN SMIALOWSKI/AFP/GettyImages)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    US President Barack Obama delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). EDITORS NOTE: Image was shot with a tilt-shift lens. AFP PHOTO Brendan SMIALOWSKI (Photo credit should read BRENDAN SMIALOWSKI/AFP/GettyImages)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama claps on stage as he accepts the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Win McNamee/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage as he accepts the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Kevork Djansezian/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage as he accepts the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Joe Raedle/Getty Images)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    First daughters Malia (L) and Sasha (C) confer as US President Barack Obama delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). AFP PHOTO Robyn BECK (Photo credit should read ROBYN BECK/AFP/GettyImages)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    First Lady Michelle Obama (R) looks over at daughters Malia (L) and Sasha (C) as US President Barack Obama delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). AFP PHOTO Robyn BECK (Photo credit should read ROBYN BECK/AFP/GettyImages)

  • US-VOTE-2012-DEMOCRATIC CONVENTION

    First Lady Michelle Obama (2nd R) looks over at daughters Malia (L) and Sasha (C) as US President Barack Obama delivers his acceptance to run for a second term as president at the Time Warner Cable Arena in Charlotte, North Carolina, on September 6, 2012 on the final day of the Democratic National Convention (DNC). AFP PHOTO Robyn BECK (Photo credit should read ROBYN BECK/AFP/GettyImages)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: (L-R) Malia Obama, Sasha Obama, and First lady Michelle Obama listen as Democratic presidential candidate, U.S. President Barack Obama speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • President Barack Obama waves to candidates at the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama waves on stage as he accepts the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama speaks on stage to accept the nomination for president during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • President Barack Obama applauds before his speech to the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/Lynne Sladky)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: (L-R) Malia Obama, Sasha Obama, and First lady Michelle Obama listen as Democratic presidential candidate, U.S. President Barack Obama speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: (L-R) Malia Obama, Sasha Obama, First lady Michelle Obama and Second lady Dr. Jill Biden watch as Democratic presidential candidate, U.S. President Barack Obama speaks during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: First lady Michelle Obama hughs Democratic presidential candidate, U.S. President Barack Obama on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama hugs his wife First lady Michelle Obama during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama waves on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: (L-R) Malia Obama, Sasha Obama, and First lady Michelle Obama watch as Democratic presidential candidate, U.S. President Barack Obama speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama walks on stage to join First lady Michelle Obama during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Streeter Lecka/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama walks on stage to join First lady Michelle Obama during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Streeter Lecka/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic presidential candidate, U.S. President Barack Obama walks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Justin Sullivan/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: First lady Michelle Obama introduces Democratic presidential candidate, U.S. President Barack Obama during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: U.S. Sen. Dick Durbin (D-IL) speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic vice presidential candidate, U.S. Vice President Joe Biden waves with his wife Second lady Dr. Jill Biden after speaking on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic vice presidential candidate, U.S. Vice President Joe Biden hugs his wife Second lady Dr. Jill Biden after speaking during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Chip Somodevilla/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic vice presidential candidate, U.S. Vice President Joe Biden speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Obama Accepts Nomination On Final Day Of Democratic National Convention

    CHARLOTTE, NC - SEPTEMBER 06: Democratic vice presidential candidate, U.S. Vice President Joe Biden speaks on stage during the final day of the Democratic National Convention at Time Warner Cable Arena on September 6, 2012 in Charlotte, North Carolina. The DNC, which concludes today, nominated U.S. President Barack Obama as the Democratic presidential candidate. (Photo by Alex Wong/Getty Images)

  • Vice President Joe Biden waves as he appears on stage to address the Democratic National Convention in Charlotte, N.C., on Thursday, Sept. 6, 2012. (AP Photo/David Goldman)