The issue:

Donald Trump has claimed repeatedly that millions of fraudulent votes were cast in the 2016 election, possibly denying him a popular-vote win.

The facts:

Washington Post research into voter fraud during the 2016 election found four confirmed instances.

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Data: electproject.org, Washington Post; Chart: Andrew Witherspoon / Axios

The 2012 Pew report that Trump has cited found many cases of incorrect voter registrations but no instances of fraud.

A 2010 News21 study concluded that almost all cases of voter fraud allegations turned out to be clerical errors or mistakes, not fraud.

Why this matters:

Trump has said he'll sign an executive order to launch a "major investigation" into voter fraud. He's raised it in interviews and in a meeting with Congressional leaders. His press secretary has faced questions over it during the White House briefing. But even the Republican chairman of the House Oversight Committee, Rep. Jason Chaffetz, says he doesn't see "any evidence."