WASHINGTON — Donald Trump publicly conceded Friday that President Obama was born in the United States, a breathtaking flip-flop after the business mogul spent five years publicly fueling false rumors and stoking conspiracy theories about the president’s birth origin.
Without explaining what changed his mind, Trump made a brief statement bluntly reversing his views and falsely accusing rival Hillary Clinton of spawning the so-called birther controversy in 2008.
The real estate magnate also falsely claimed that he was the one who put the issue to rest. In fact, Trump has been one of the leading cheerleaders since 2011 for a discredited line of attack on Obama that is widely viewed as racially motivated, aimed at delegitimizing the nation’s first African-American president.
But now that Trump has essentially tied Clinton in general election polls and is attempting to appear more mainstream and disciplined after more than a year of erratic campaigning, he has jettisoned one of his core appeals to the Republican fringe that helped fuel his rise in American politics and his victory in the 2016 GOP primary.
“President Barack Obama was born in the United States, period,” Trump declared in a 30-second statement delivered in Washington at his new hotel on Pennsylvania Avenue.
“Now, we all want to get back to making America strong and great again,” he said at the end of his uncharacteristically brief remarks. He refused to elaborate as reporters called out for an explanation of his change of heart more than five years after Obama released his “long-form’’ birth certificate proving he was born in Hawaii.
Trump might have hoped his statement would put the issue to rest. But Democrats, led by Clinton, expressed outrage at Trump’s maneuver and clearly do not intend to let Trump off easily.
Clinton demanded that Trump apologize to Obama and the American people for being a leader of the birther’ movement for most of Obama’s presidency.
Trump’s campaign was ‘‘founded on this outrageous lie. There is no erasing it in history,’’ the Democratic nominee said at an event with black women. Trump is ‘‘feeding into the worst impulses, the bigotry and bias that lurks in our country,’’ Clinton said.
Trump announced his shift 10 days before the first presidential debate, scheduled for Sept. 26. He appeared to be attempting to be getting ahead of an issue that is a likely line of questioning from the moderator and line of attack from Clinton. A Suffolk university poll earlier this month found 44 percent of respondents believe Trump is racist, including 40 percent of those who were undecided between Trump or Clinton.
Trump’s change of posture did not appear to come easily. In an interview with The Washington Post on Wednesday, the billionaire real estate mogul refused to say whether he thought Obama was born in the United States. His campaign then issued a statement Thursday night saying Trump said Obama was born in the United States. But even on Friday morning, hours before Trump appeared before cameras, he refused to engage with Fox News on the issue, saying he wanted to keep the suspense alive.
Then he convened the press at his newest hotel in Washington, in the Old Post Office Building on Pennsylvania Avenue, and had a lineup of veterans endorse him at the podium for 25 minutes. When he finally stepped up to make his declaration about the president’s birth, it lasted only about 30 seconds.
‘‘Hillary Clinton and her campaign of 2008 started the birther controversy. I finished it,’’ Trump said. ‘‘I finished it, you know what I mean.’’
There is no evidence that Clinton or her 2008 campaign spread birther questions about Obama during their 2008 primary contest, although fact-checkers have found some of her supporters trafficked in the rumors.
On Friday, a former Washington bureau chief for the McClatchy chain of newspapers, James Asher, said from his Twitter account that Clinton confidant Sid Blumenthal urged him to investigate Obama’s birthplace during the 2008 campaign. Blumenthal flatly denied the allegation in an e-mail to the Globe.
“This is false. Period,’’ Blumenthal wrote.
Trump also did not “finish’’ the supposed controversy, as he claimed Friday. Instead, he has given numerous interviews and repeatedly tweeted about the issue in the last five years, sometimes directly raising questions about Obama’s birth or making coy allusions that Obama may have been born overseas. The news site Slate compiled dozens of Trump’s birther tweets, most during 2012 and 2013.
“An ‘extremely credible source’ has called my office and told me that @BarackObama’s birth certificate is a fraud,’’ Trump tweeted in 2012. A few weeks later, he took to Twitter again: “Why do the Republicans keep apologizing on the so called ‘birther’ issue? No more apologies — take the offensive!’’
Trump’s statements resonated strongly in the dark corners of the Internet and on right-wing websites, where bloggers have spent years hours trying to raise doubts about Obama’s eligibility to serve.
Twenty percent of Americans said they believe Obama was born outside the United States in a recent CNN/ORC poll. The figure included 9 percent who say there is solid evidence Obama was not born here; 11 percent said they just suspected he was born abroad.
The same poll found that 29 percent of adults surveyed think Obama is a Muslim (he’s a Christian), including 43 percent of Republicans.
Trump’s assertion Friday that he “finished’’ the controversy apparently refers to Obama’s decision in 2011, in the face of repeated challenges from Trump and others, to release his “long-form’’ birth certificate.
Trump’s campaign put out a statement Thursday night that said he would be making a statement on Friday and tried to cast Trump as a hero rather than instigator of the birther movement, claiming Trump brought “this ugly incident to its conclusion by successfully compelling President Obama to release his birth certificate,” which the Trump campaign deemed “a great service” to Obama and the country.
Obama briefly addressed Trump’s reversal on Friday when asked by reporters covering a photo opportunity at the White House.
‘‘We’re not going to be able to solve our problems if we get distracted by sideshows and carnival barkers,’’ he said. ‘‘I was pretty confident about where I was born. I think most people were as well.’’
Michelle Obama also waded in, while stumping in Virginia for Clinton.
“There were those who continued to question for the past eight years up through this very day whether my husband was even born in this country,’’ she said. “Well, during his time in office, I think Barack has answered those questions with the example he set by going high when they go low.”
Obama’s job approval has soared as high as 58 percent and now averages 51 percent, as measured among polls tracked by the website Real Clear Politics. Meanwhile, Trump has shown he is vulnerable among college-educated white voters in places like the suburbs of Virginia, Ohio, Pennsylvania, and Florida, crucial swing voting blocs that are likely to be squeamish about Trump’s conspiracy theories.
Jon McHenry, a Republican pollster and strategist, said “it just strains credulity” that Trump suddenly changed his views on Obama’s birthplace. Rather he sees the move as a sign that campaign strategists “got to call the shots today,” advising Trump that he needs to declare Obama legitimate if he wants to win any votes from suburban women.
Other top-level Clinton surrogates seized the opportunity to talk about Trump’s history pushing the birther email@example.com. Follow her on Twitter @vgmac.