Twitter claims 'no evidence' of mail-in voter fraud despite numerous convictions since 2016

Twitter this week slapped a warning label on some of Donald Trump's tweets for the first time, cautioning users that the president's "series of claims about potential voter fraud" were "unsubstantiated," citing "CNN, Washington Post and others" for authority. "Experts say mail-in ballots are very rarely linked to voter fraud," Twitter declared.

In an accompanying "What you need to know" list, the social media giant added that "fact checkers say there is no evidence that mail-in ballots are linked to voter fraud."

In fact, there have been numerous cases of mail-in voter fraud scattered widely across the country over the past four years, evidence that the absentee ballot system is open to at least some voter manipulation, even as many experts and pundits continue to insist otherwise. 

According to data compiled by the Heritage Foundation, there have been around three dozen criminal convictions for absentee ballot fraud over the past four years, and those cases are but a small subset of over 200 convictions for various types of voter fraud the conservative organization says have occurred since 2016.