Donald Trump speaks at a campaign rally, May 25, 2016 in Anaheim, California.(ROBYN BECK/AFP/Getty Images)

Update: In an interview published on the evening of Thursday, Sept. 15, a day after it was conducted, Donald Trump would not say whether he believed President Obama had been born in Hawaii. “I’ll answer that question at the right time,” Trump told The Post's Robert Costa. “I just don’t want to answer it yet.” Hours later, Donald Trump's campaign released a statement indicating that Trump believed President Obama was born in the United States. That statement says that Trump "was finally able to bring this ugly incident to its conclusion" in 2011. As the timeline below makes clear: he didn't.

It began on ABC's "Good Morning America" in March 2011.

"Everybody that even gives any hint of being a birther -- a word you didn't use -- even a little bit of a hint, like, gee, you know, maybe, just maybe, this much of a chance: They label them as an idiot," Donald Trump told Ashleigh Banfield when she asked if he thought President Obama was born in America. "Let me tell you. I'm a really smart guy. I was a really good student at the best school in the country. The reason I have a little doubt -- just a little! -- is because he grew up and nobody knew him. When you interview people -- if I ever got the nomination, if I ever decide to run -- you may go back and interview people from my kindergarten, they'll remember me. Nobody ever comes forward. Nobody knows who he is until later in his life. Very strange. The whole thing is very strange."

(Shortly after Obama was inaugurated, Obama's old kindergarten teacher was interviewed. She remembered him: "cute, likable" -- and chubby.)

The ABC interview was titled, "Trump a Birther?" Within days, Trump ensured that nearly everyone knew the answer: Yes.

Donald Trump spent a lot of time raising doubts over President Obama's birth certificate in 2011. He finally admitted Obama was born in the U.S. on Sept. 16, but falsely accused Hillary Clinton's campaign of starting the rumor. (Peter Stevenson/The Washington Post)

For a month-and-a-half Trump pressed the issue, clearly caught in a feedback loop with the press attention. It was in early April that Trump told the world that he had a team of investigators researching Obama's background, including in Hawaii. "I have people that have been studying it," he told CNN, "and they cannot believe what they're finding."

One of the first people to weigh in on Trump's comments after that "Good Morning America" appearance was former New York City Mayor Rudy Giuliani.

"He's born in the United States, I don't see any real question about that," Giuliani told Politico. "And even if some people have some doubts in the back of their minds it's really too late and futile. ... We have so many more important things to talk about."

This week, in his new role as an advocate for Trump, Giuliani addressed Trump's history of birtherism in an interview on MSNBC, saying that Trump disavowed having questioned Obama's legitimacy "two years ago — three years ago."

That's not true. From 2011 until now, there's no indication that Trump has backed off, even after declaring victory on getting the president to provide his birth certificate.

Obama released the document at the end of April 2011, shortly before the White House correspondents’ dinner at which Trump was mercilessly mocked by both Seth Meyers (who was hosting the event) and the president himself. When the birth certificate came out, Trump crowed about having been the person to force the issue.

"I'd want to look at it, but I hope it's true so that we can get on to much more important matters," Trump said at a press conference shortly after the release. "I am really honored, frankly, to have played such a big role in hopefully -- hopefully! -- getting rid of this issue."

He wasn't letting Obama off the hook that easily, though. "Now, we have to look at it. We have to see: Is it real? Is it proper? What's on it? But I hope it checks out beautifully."

It didn't take long for Trump to decide that the answers were no and no.

Two weeks after the document was released, birthers at WorldNetDaily started questioning its validity. In August, Sheriff Joe Arpaio -- also now a Trump supporter -- announced that he planned to travel to Hawaii to investigate whether or not it was real. The following March, Arpaio announced that his analysis suggested it might be forged. (This analysis has not been corroborated by any reputable source.)

After Arpaio's announcement, Trump sent him a note. "Joe," it read, "Great going -- you are the only one with the 'guts' to do this -- keep up the good fight."

Between March 2012 and November 2014, Trump tweeted about Obama's birthplace and the birth certificate a number of times. He also on multiple occasions called Obama "Barry Soetoro." Soetoro was the last name of his step-father with whom he lived in Indonesia; "Barry Soetoro" is used by birthers to hint at some subterfuge in Obama's past. (That includes the easily-debunked claim that he attended Columbia University as a foreign student.)

This is probably the most significant tweet since it undercuts Giuliani's recent claim, though:

Fewer than seven months before he announced his intention to run for president, Trump was retweeting claims that Obama's birth certificate was forged.

The subject came up as Trump was exploring a possible run, and then after he announced. In July 2015, NBC's Katy Tur asked Trump why people should believe the data he was offering about crime and illegal immigrants when he'd spent so long claiming that Obama was born outside the United States, which "turned out not to be true."

"Well, I don't know," Trump replied. "According to you it's not true. Well, I don't know."

That was a little over a year ago.

When Trump raised questions about Ted Cruz's nativity earlier this year, CNN's Wolf Blitzer asked if he believed Obama was a natural-born citizen.

"Who knows, who knows, who cares right now," he said. "I have my own theory on Obama someday. I'll write a book. I'll do another book, it'll do very successfully."

That was in January. Over the intervening eight months, Trump has not indicated that his view has changed.