Is he no longer a birther?
As Trump approaches the general election and needs not just his rabid base of voters but others to support him, he has made some attempts to soothe anxieties about his methods, his rhetoric and his temperament. An appearance at a largely African-American church in Detroit has been widely interpreted as an effort to reassure those who fear he is racist.
Rudy Giuliani's claim that Trump is no longer holding to his birther doubts would represent another move toward the mainstream. But as a man who generally likes to keep all his options open, and his rhetoric obscure, Trump has yet to affirm the former New York mayor's statement.
Trump has been in this position before, on other issues. He has never corrected himself on his claims that he saw, on TV, throngs of Muslim-Americans celebrating the 9/11 attacks in New Jersey (a claim for which there is no evidence). Likewise, he has never corrected himself about Obama's status as the "founder" of ISIS or his criticism of an American-born judge who he said wouldn't be fair to him because he is "Mexican." Indeed, Paul Ryan, the Republican Speaker of the House of Representatives, declared that statement racist -- but Trump never disavowed it.
Trump doesn't publicly change his mind, apologize or admit to error because his public persona has been built, since the 1970s, on the idea that he is a tough man who never backs down.
To do it once would be to open up the possibility that other tough-guy stands he has taken may have been in error. The edifice of his ego, like a house of cards, is too fragile for him to allow this. Don't expect him to do it now, no matter what Rudy Giuliani says.