In Arizona, where Republicans are hoping to oust freshman Sen. Mark Kelly, possible candidates include state Republican Party Chairwoman Kelli Ward and Rep. Andy Biggs, leader of the House Freedom Caucus — and key amplifiers of Trump’s unfounded voter fraud claims. In Georgia, GOP hopes of ousting Sen. Raphael G. Warnock (D) could rest in the hands of a primary voter base that remains squarely focused on the results of the 2020 election.

The picture is more unsettled in the key swing states of Pennsylvania and North Carolina — where longtime GOP Sens. Patrick J. Toomey and Richard Burr, respectively, are departing — but among the rumored potential candidates in the latter state are Lara Trump, the former president’s daughter-in-law…

“You give Democrats an opportunity when you run candidates that are that divisive and that contentious,” said J.B. Poersch, the president of the Senate Majority PAC, the largest Democratic super PAC focused on the Senate. “The fact that this stuff is breeding in these [Republican] states tells you that there’s a danger of it occurring across several states.”

In Missouri, the fears of nominating the wrong Republican are especially high, with memories of the 2012 race between Democratic Sen. Claire McCaskill and Rep. Todd Akin (R) still fresh in many GOP minds.