Well, now it should stop:— Donald J. Trump (@realDonaldTrump) February 7, 2019
PRESIDENTIAL HARASSMENT! It should never be allowed to happen again!
In 2010, at the urging of Donald Trump's lawyer Michael Cohen, the National Enquirer began promoting a potential Trump presidential campaign, and with Cohen's involvement, the tabloid began questioning Obama's birthplace and citizenship.
In March 2011, during an interview on Good Morning America, Donald Trump said he was seriously considering running for president, that he was a "little" skeptical of Obama's citizenship, and that someone who shares this view should not be so quickly dismissed as an "idiot" (as Trump considers the term "birther" to be "derogatory"). Trump added, "Growing up no one knew him", a claim ranked Pants-on-Fire by Politifact. Later, Trump appeared on The View repeating several times that "I want him [Obama] to show his birth certificate." He speculated that "there [was] something on that birth certificate that [Obama] doesn't like", a comment which host Whoopi Goldberg described as "the biggest pile of dog mess I've heard in ages." On the March 30, 2011, edition of CNN Newsroom, anchor Suzanne Malveaux commented on Trump's statements, pointing out that she had made a documentary for which she had gone to Hawaii and spoken with people who knew Obama as a child. In an NBC TV interview broadcast on April 7, 2011, Trump said he would not let go of the issue, because he was not satisfied that Obama had proved his citizenship. After Trump began making his views public, he was contacted by Joseph Farah of WorldNetDaily, who was reportedly on the phone with Trump every day for a week, providing Trump with a "birther primer", answers to questions, and advice. After Obama released his long-form birth certificate on April 27, 2011, Trump said "I am really honored and I am really proud, that I was able to do something that nobody else could do."
On October 24, 2012, Trump offered to donate five million dollars to the charity of Obama's choice in return for the publication of his college and passport applications before October 31, 2012.
On September 16, 2016, as the Republican Party presidential nominee, Trump conceded that "President Barack Obama was born in the United States. Period." Trump gave himself credit for putting the controversy to rest and also repeated a false claim that Hillary Clinton, his opponent in the 2016 U.S. presidential election and one of Obama's opponents in the 2008 Democratic presidential primaries, had started the controversy concerning Obama's place of birth. While those who did so were Clinton supporters, there is no evidence of Clinton or her campaign questioning Obama's birthplace.
Publicly he finally conceded the fact; but privately, as recently as late November, 2017:
In recent months, they say, Mr. Trump has used closed-door conversations to question the authenticity of President Barack Obama’s birth certificate. He has also repeatedly claimed that he lost the popular vote last year because of widespread voter fraud, according to advisers and lawmakers.
One senator who listened as the president revived his doubts about Mr. Obama’s birth certificate chuckled on Tuesday as he recalled the conversation. The president, he said, has had a hard time letting go of his claim that Mr. Obama was not born in the United States. The senator asked not to be named to discuss private conversations.
Trump's Twitter archive just on the topic of birtherism runs from 2011 to 2014, or one year longer than he's been in office.
Amazing how much he has accomplished, isn't it? Nancy Pelosi provides the applause:
PELOSI on Trump's "presidential harassment" tweet: "I am not commenting on what the president has to say about our work. I always think whatever the president says about us, he's projecting his own unruly-ness. He's a projector and that's what it's about." pic.twitter.com/1Cp6LnZx4b— Aaron Rupar (@atrupar) February 7, 2019