The 2024 election is a wager.
The wager on each side is that the other party’s presumptive nominee can’t win.
Of no other election in my lifetime has that been true. The 2016 race came close, insofar as each party’s nominee was loathed by the opposition. But Republicans never believed Hillary Clinton couldn’t win. The point of the “Flight 93 election” nonsense, in fact, was that Clinton was likely to win and to replace Antonin Scalia with a communist. The threat was urgent, so it called for urgent action.
The 2020 election doesn’t quite work, either. Joe Biden was very old, yes, but not very, very old like he is now. He wasn’t despised personally the way Hillary was, he was qualified for the job, and he was blessed with an opponent who’d presided over a pandemic and the ensuing economic calamity. It was easy to imagine him winning—and he did.
In 2024, however, large chunks of voters in each party seem to find it inconceivable that their candidate might lose to the incompetent and corrupt fool opposing him.