Though the figures are preliminary, they provide a window into Democratic enthusiasm ahead of the election and offer a warning for Republicans. While Democrats stockpile votes and bring in new supporters, Trump’s campaign is relying on a smooth Election Day turnout operation at a time when it’s confronting an out-of-control pandemic and a mounting cash crunch.

“A ballot in is a ballot in, and no late-campaign message or event takes it out of the count,” said Chris Wilson, a GOP pollster who specializes in data and analytics. “Bottom line is that means that Biden is banking a lead in the mail and more of the risk of something going wrong late is born by Republicans because our voters haven't voted yet.”

Republicans acknowledge Democrats have established a lead, though some stressed it was early and compared it to a basketball team winning the opening tip-off. Trump aides argue that the Democratic advantage will make little difference in the end, saying the opposing party is merely frontloading voters who otherwise would have voted on Nov. 3.

They also note that while Trump has repeatedly bashed mail-in voting — virtually ensuring that most of his supporters cast ballots in-person on Election Day — Democrats are placing a heavy emphasis on it. An NBC News/Wall Street Journal poll released last month showed that nearly half of Biden’s supporters planned to vote by mail, compared to just about one-tenth of Trump supporters.

The Trump team points to special congressional elections earlier this year in red-tinted New York and Wisconsin districts where Republicans trailed in absentee voting but ended up with a substantial advantage among voters who cast ballots on Election Day, giving them wins in both contests.

“The majority of our voters prefer to vote in-person. So, we expect to be well behind on absentee requests as Democrats have made it their mission to push for an all-mail election that brings fraud and chaos into the system. You’ll see Democrats predominantly vote by mail, and our voters will come out in droves to vote in-person,” said Mike Reed, a Republican National Committee spokesperson.

But the data also shows that Democrats are attracting new supporters in small but potentially significant numbers in states they narrowly lost in 2016.

In Pennsylvania, which Trump won by just 44,000 votes four years ago, Democrats have built a lead of nearly 100,000 ballot requests from voters who didn’t participate in the 2016 election but are preparing to vote by mail this year, according to TargetSmart’s figures. In Michigan, where Trump won by fewer than 11,000 votes (and where voters do not register by party), the firm’s model shows that Democratic-aligned voters have a nearly 20,000-person advantage among non-2016 voters signing up to receive ballots. In Wisconsin, which Trump won by 22,000 votes, Democratic-leaning voters who skipped 2016 have made nearly 10,000 more requests for this election than their GOP counterparts.

Republicans are also encouraging supporters to vote absentee. Through telephone calls, digital advertising and mailers, they have prodded Trump backers to vote early or by mail. The pro-Trump outside group America First Action, meanwhile, has been following up with voters to ensure they are turning in their ballots.

Yet Trump — much to the frustration of senior Republicans — has undermined those efforts with repeated attacks on mail-in voting. The president has used his recent public appearances and his Twitter feed to savage voting by mail as a process that can’t be trusted.

“It's a case of what Trump actually says mattering a lot more than what his campaign does. The campaign is working hard to get absentees requested and, soon, returned; but Trump bashing mail voting repeatedly makes strong Republicans much less likely to do it,” Wilson said.