One reason Republicans are more concerned at this point is because Trump and the GOP have for many months now cast doubt on the electoral process, in particular the use of mail voting. Historically, mail voting hadn’t been a partisan issue, but now most Republicans don’t trust it: In that NBC News/SurveyMonkey poll, 79 percent of Republicans said they opposed changing election laws to allow everyone to vote by mail, though 53 percent of Americans overall supported the idea.

Other surveys have also found that Republicans have more doubts about the fairness of the election. A poll released on Monday by Monmouth University found that 39 percent of registered voters weren’t confident that the election would be conducted fairly and accurately, including 44 percent of Republicans and 31 percent of Democrats. Meanwhile, in The Economist/YouGov’s weekly poll, 28 percent of registered voters said they had only a little confidence or none at all that the 2020 election would be held fairly. The differences by party were smaller here — 30 percent of Republicans and 24 percent of Democrats held this view — but Democrats were more likely to say they had a great deal or quite a bit of confidence in the election (44 percent) than Republicans (32 percent).

Overall, Democrats have more confidence about the election than Republicans, but there is plenty of doubt, too.