The White House on Tuesday stuck firmly to President Donald Trump's claim that millions of people voted illegally in the November election, but provided no evidence to back up his assertion.
Trump spokesman Sean Spicer said the president "does believe" that he lost the popular vote to Democrat Hillary Clinton only because of widespread illegal ballots.
Spicer said Trump's belief is based on "studies and evidence."
"He believes what he believes, based on the information he was provided," Spicer said. But he would not detail what information he was referring to, citing only a 2008 Pew study that he said showed 14 percent of people who voted were not citizens.
David Becker, executive director of the Center for Election Innovation & Research, and one of the authors of the Pew report cited by Spicer, rebutted the claim in a tweet Tuesday, saying that "voting integrity better in this election than ever before. Zero evidence of fraud."
As NBC News reports, Becker also tweeted in November in response to a similar unsubstantiated claim from Trump.
"We found millions of out of date registration records due to people moving or dying, but found no evidence that voter fraud resulted," Becker wrote.
Spicer, who spent several years at the Republican National Committee before joining the White House, would not say whether he shared the president's belief. He also sidestepped questions about whether the White House would investigate the voter fraud allegations, saying only, "Anything is possible."
Trump first raised the prospect of illegal voting during the transition. Then, during a reception with lawmakers at the White House Monday evening, he again claimed that he'd lost the popular vote because 3 million to 5 million immigrants living in the U.S. illegally had voted. That's according to a Democratic aide familiar with the exchange who spoke on condition of anonymity to discuss the private meeting.
Critics from both sides of the aisle have called on the president to put this issue to rest. As NBC News reports, Sen. Lindsey Graham, R-S.C., pleaded with Trump Tuesday to stop repeating the widely debunked claim.
"To continue to suggest that the 2016 election was conducted in a fashion that millions of people voted illegally undermines faith in our democracy," Graham told reporters. "It's not coming from a candidate for the office, it's coming from a man who holds the office. So I am begging the president, share with us the information you have about this or please stop saying it."
Democratic lawmakers denounced the inaccuracy of the president's statement as well, with Sen. Bernie Sanders, I-Vermont, calling the claims "nonsensical" and "delusional."
"When Trump talks about 3 to 5 million people voting illegally he is sending a message to every Republican governor in this country to go forward with voter suppression," Sanders said.
Some Republicans, however, are supporting Trump's claim. Senate Majority Leader Mitch McConnell, R-Kentucky, would not say whether he agreed with the president, though he told NBC News that "the notion that election fraud is a fiction is not true."
Rep. Steve King, R-Iowa, said Tuesday "there is data out there" to back up the president's claim, though he believes the number of illegal votes may be slightly lower, closer to 2.4 million. He told NBC News that he reached that figure by extrapolating on "how many illegals could have or could be voting in the United States."
Trump's assertion appears to be part of a continuing pattern for him and his new administration in which unverified or unverifiable claims overshadow his outreach efforts. Both Trump and Spicer made unsubstantiated comments over the weekend about the crowds who gathered for the inauguration.
Aides and associates of the president say that he is dogged by insecurity over his loss of the popular vote and believes Democrats and the media are questioning the legitimacy of his presidency. On Tuesday, the president tweeted a photograph from the inauguration taken from an angle that accentuated the crowd and said he planned to hang the image in the press area of the White House.