04/12/2011 12:27 pm ET Updated Jun 12, 2011

Donald Trump: White House 'Concerned' Because I'm Raising Birthplace Issue

According to potential presidential contender Donald Trump, the White House is "concerned" because he's stepping up to the plate to challenge the president on whether or not he was born in the United States.

Trump made the suggestion to the New York Daily News this week after senior White House adviser David Plouffe said, "There is zero chance that Donald Trump would ever be hired by the American people" to be president. Addressing the billionaire's ambitions for the next election cycle during an appearance on ABC's "This Week," Plouffe called Trump's fervent effort to raise doubt over where the president was born "sideshow behavior."

In responding to the remarks, Trump told The Daily News, "I know for a fact that I am the only candidate they are concerned with." He added, "He should focus on properly dealing with the Chinese, the Saudis and all of the other nations that are ripping off the United States instead of making up quotes about Donald Trump."

The controversy comes despite the fact that the president's birth certificate has been available online for more than three years.

A new poll shows Trump making headway in locking up support from Republicans in the early stages of the race for the GOP presidential nomination. CNN reports:

But while a CNN/Opinion Research Corporation survey released Tuesday indicates that the real estate mogul and reality TV star has nearly doubled his support since mid-March, it doesn't mean he has smooth sailing ahead.

"More than four in ten Republicans say they would not like to see Trump toss his hat in the ring," says CNN Polling Director Keating Holland.

Karl Rove and Sen. Marco Rubio (R-Fla.) are two conservatives who have expressed dissatisfaction with the fact that Trump continues to hammer the birthplace issue. Alternatively, while Sarah Palin has signaled she believes the president was born in the United States, she recently said "more power to" Trump for looking into the matter.