States are expecting an increase in voters wanting to mail in their ballots as the coronavirus pandemic has made in-person voting potentially dangerous. And some — most notably the president — have questioned whether mail-in ballots are secure. President Donald Trump has repeatedly said voting by mail has a high potential for voter fraud, despite recently casting an absentee ballot in Florida himself. But officials in states that conduct elections entirely by mail say fraud is extremely rare, and they also have measures in place to protect against ballot tampering. The question for other states is whether, and how quickly, they can ramp up similar protections ahead of November. Trump and others questioning the security of mail-in ballots do have a recent, high-profile example in North Carolina's 9th District, where the 2018 election results were thrown out after a Republican political consultant was accused of tampering with absentee ballots. Proponents of voting by mail pushed back, arguing that there is little evidence of fraudulent ballots and that no system is perfect. "If someone really wants to perpetrate fraud, I think they probably could in any system, including voting at a polling place," said Washington Secretary of State Kim Wyman, a Republican. "So no system is completely free of the potential of fraud."