On the day Romney was projected the winner of the Texas Republican primary and that he would collect enough delegates to clinch the GOP presidential nomination, The New York Times reported Trump, the real estate magnate and reality TV star, showed no sign of backing off from his "birther" theory that Obama was not born in Hawaii in 1961.
"Nothing changes my mind," Trump said on CNBC Tuesday, repeating his doubts about the president's Hawaiian birth certificate. "I walk down the street and people are screaming, 'Please don't give that up.'"
During an interview with CNN's Wolf Blitzer Tuesday, Trump said "a lot of people do not think it was an authentic certificate," but when asked who he was talking about he declined to give any names.
When Blitzer brought up newspaper announcements of Obama's birth in 1961 in Hawaii, Trump said, "Can you stop defending Obama?"
"Donald, you're beginning to sound a little ridiculous, I have to tell you," Blitzer said.
"You are, Wolf," Trump responded. "Let me tell you something, I think you sound ridiculous."
Romney was asked Monday night if he had reconsidered campaigning with Trump, CBS News reported.
"You know, I don't agree with all the people who support me and my guess is they don't all agree with everything I believe in," the former Massachusetts governor said. "But I need to get 50.1 percent or more, and I'm appreciative to have the help of a lot of good people."
The Obama campaign released a Web ad showing Sen. John McCain, R-Ariz., as a Republican presidential candidate, discrediting myths about Obama and calling on Romney to do the same.
The ad shows parts of Trump interviews in which he questions Obama's birthplace.
NBC News reported video recording was not permitted at the Las Vegas event Tuesday, which was expected to bring in about $2 million for the Romney campaign.