That may be partly because voters in the current hyper-polarized climate are drawn to excuses for losses, such as cheating, said Matthew Germer, the governance director at R Street Institute, a conservative organization. Another factor: These lies make money for the liars.

“Conspiracy theories are great for fund-raising, and terrible for democracy,” Mr. Germer said. “And that, again, is preying on our tendencies to want to be on a winning side.”

He added, “I’m optimistic that the more of these conspiracies that crumble, that it undermines the credibility of those who are promulgating them.

“People can really only put up with so much,” he said. “But I guess it remains to be seen where those limits lie and how long it can last.”