HOUSTON — Vice President Joe Biden rallied support for President Barack Obama before the nation's largest civil rights organization on Thursday, declaring that Republican challenger Mitt Romney's election-year agenda would hurt – not help – working families in the black community.

Biden, appearing before the NAACP's annual convention one day after Romney addressed the group, offered what amounted to a rebuttal of the Republican rival as both campaigns sought support from a key constituency in several swing states.

The vice president did not specifically cite Romney's argument to the NAACP on Wednesday that he could serve African-Americans better than Obama, the nation's first black president. Romney was booed when he said he'd repeal Obama's sweeping health care reform law but otherwise got a polite reception as he reached out to a traditionally Democratic voting bloc.

Biden predictably drew a far more rousing reception as he outlined differences between Obama and Romney on health care, education, energy, women's rights and research, saying the two rivals had "fundamentally different visions."

Biden offered a rundown of Obama's first term, pointing to a landmark health care law, launching the mission that killed al-Qaida leader Osama bin Laden and the decision to rescue the financial system and U.S. automakers General Motors and Chrysler.

"I believe this election will come down to character, conviction and vision. And it will not surprise you – I don't think it's even a close call," Biden said. "So it's time, it's time for the NAACP to do what it's always done ... To stand up. Make our case. Stand our ground. And make real our vision for America."

Obama did not speak to the National Association for the Advancement of Colored People this year, appearing instead in a taped video message. In the brief remarks, Obama said: "I stand on your shoulders and at the NAACP you have always believed in the American promise." He reiterated many of the themes of his re-election campaign, saying the nation needs to "build an economy where everyone can have the confidence that the hard work will also pay off."

The president said he was sorry he couldn't be there in person. Obama had no public events scheduled Thursday but was to be interviewed at the White House, along with first lady Michelle Obama, by Charlie Rose of CBS News.

White House officials noted that Obama spoke to the NAACP convention during the 2008 presidential campaign and in 2009, while Mrs. Obama addressed the group in 2010. The president is scheduled to address the National Urban League in New Orleans on July 25.

Black voters are a key part of Obama's re-election strategy, with about 95 percent supporting him in 2008. Polls have shown black voters supporting Obama at comparable levels this year but Romney could undercut the president in states with large black communities, such as North Carolina, Virginia, Ohio and Florida, if he can persuade some black voters to support him or if they stay home on Election Day.

Romney said Wednesday that much more must be done to improve education in the nation's cities and noted that the 14.4 percent unemployment rate among blacks is higher than the 8.2 percent national average.

"If you understood who I truly am in my heart, and if it were possible to fully communicate what I believe is in the real, enduring best interest of African-American families, you would vote for me for president," Romney said.

In Obama's absence, Biden offered a fiery defense of administration policies while warning of what a Romney presidency would bring to civil rights. He asked attendees to "imagine" what the Justice Department would be like under a Romney administration and "imagine when his senior adviser on the Constitution is Robert Bork," the Republican Supreme Court nominee who was defeated by Democrats in 1987. Biden was chairman of the Senate Judiciary Committee at the time.

Biden received sustained applause throughout his address. When he spoke about civil rights and administration efforts to expand voting rights and not diminish them, the crowd stood and loudly cheered. When Biden said, "Did you think we'd be fighting these battles again?" people in the crowd answered in unison, "No."

Biden said there was a lot more he could say on protecting voting rights but that he was "preaching to the choir." "Say it, say it," many in the crowded responded. As Biden was wrapping up, he said, "Let me close, my friends," prompting members of the audience to boo and yell, "No!"

___

Thomas reported from Washington.

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