President Trump at his inauguration Friday. Trump’s false assertion that millions of people voted illegally in the last election is striking at the heart of democracy. (Jonathan Newton /The Washington Post)

There is no benign explanation for President Trump’s false assertion that millions of people voted illegally in the last election. It is either a deliberate attempt to undermine faith in the democratic process, an exhortation to those who favor new restrictions on access to the ballot box or the worrisome trait of someone with immense power willing to make wild statements without any credible evidence.

By repeating as president what he had said as a candidate, for whatever purpose, Trump is striking at the foundation of a democratic society. This is yet another example of Trump being willing to cast doubt on information, individuals or institutions that he believes threaten his legitimacy, challenge his authority or question his actions — from attacks on “phony polls” or the “dishonest media” to assertions now of vast voter fraud.

This is not a debate about the size of the crowd at last week’s presidential inauguration. That is a piddling controversy compared with his claim that the election system overseen by the states is somehow riddled with fraud. Trump is chipping away at a shared public confidence in a system that is fundamental to a representative government for no apparent reason other than that he’s bothered by the fact that, although duly elected and now in the White House, he lost the popular vote to Hillary Clinton by almost 3 million votes.

Trump has virtually no elected allies in this assault on the election system. A smattering of Republicans might be willing to say that what Trump claims is at least plausible, as Rep. Steve King (R-Iowa) did on MSNBC on Tuesday. But the vast majority of those in Trump’s party share the view of House Speaker Paul D. Ryan (R-Wis.), who told reporters Tuesday that he has seen no evidence to buttress what Trump said at a meeting with the bipartisan congressional leadership Monday at the White House

Pelted on Tuesday with questions about Trump’s claim, White House press secretary Sean Spicer danced his way through the daily briefing. Asked for evidence to back up what Trump said, Spicer responded by saying simply that this is something the president has long believed. Tellingly, Spicer, the former chief strategist at the Republican National Committee, would not put his own credibility on the line by saying he believed what his boss had said. “What does it mean for democracy?” CNN’s Jeff Zeleny asked Spicer. “It means I’ve answered your question,” Spicer responded, then moved to another reporter.

(Bastien Inzaurralde/The Washington Post)

Sen. Lindsey O. Graham (R-S.C.) implored Trump to stop repeating the indefensible. He said Trump could find himself in a situation where he undermines his own credibility. People will begin to doubt what Trump says, Graham warned. Many already do. But Graham must know that the president isn’t listening to that kind of advice. Trump will say what he wants when he wants. However, now that he is president, his words matter more than ever. Candidate Trump complained that the system was rigged. A president who says that, without evidence, is playing with fire.

[What the studies of voter fraud and voter rolls have shown]

Democrats have been quick to condemn Trump. To Trump, that’s to be expected and probably will reinforce in him the belief that he’s onto something real. Republicans, while not agreeing with the president, appear to want to pretend that what he is doing, if not exactly harmless, does not warrant their serious attention or a confrontation. They prefer to turn away, shake their heads about their president and hope that he stays focused on the issues on which he campaigned. Vice President Pence was among those Tuesday who wanted no part of the discussion about voter fraud.

Trump has claimed that studies back up his belief. Those studies, however, prove no such thing. A 2012 Pew study found that about 1.8 million deceased people were still on the rolls and that 2.75 million people were registered in two states. The study called for states to clean up their voter rolls but did not draw conclusions about voter fraud.

Spicer incorrectly claimed that the Pew study showed that 14 percent of voters were noncitizens. That was a different study that was later debunked by other social scientists. One attempt to quantify cases of voter impersonation fraud over a period of years found just three handfuls of cases out of about a billion ballots cast. Dartmouth College conducted a post-election study of the 2016 results and found “no evidence of widespread voter fraud.”

[Fury, tumult and a reboot: Inside the White House]

Still, in a time of hyper-partisanship, doubts about the credibility of elections exist. Pre-election polling by The Washington Post and ABC News found that between 1 in 5 and 1 in 6 Americans said voting by people who were ineligible happened “very often.” A September survey found that, overall, 47 percent of likely voters said it happened either “very” or “somewhat” often.

(Reuters)

Before the election, Democrats expressed more confidence in the accuracy of the voting system than did Republicans. After the election, based on polling by the Pew Research Center, Democrats and Republicans were about equally confident in the credibility of the vote counts. Democrats had become less confident, Republicans more confident as a result of Trump’s victory. Many Trump supporters agree with the president that voting by undocumented immigrants is commonplace and widespread.

In some ways, Trump is off to a fast start to his presidency, with the signing of executive orders that have cheered various parts of his disparate constituency. His Cabinet isn’t fully in place but his nominees appear likely to win confirmation. He will offer a Supreme Court nominee next week, he said Tuesday. That nomination will probably touch off a partisan battle but further cement his standing with the Republican base.

Early Wednesday, the president tweeted that he would ask for a “major investigation” into voter fraud. But it is far from clear what the scope of this possible investigation would be, what Trump’s real intentions are in calling for it (though he suggested strengthening voting procedures as a possible goal) or who would conduct it. Everyone should wait to hear more. The president has preferred his own version of what happened in November in the popular vote, even if that damages the very system of government atop which he now sits.

The next move is now his.

An earlier version of this report incorrectly referred to Dartmouth College as a university.