I took a vacation last week and a fresh look at the midterm results and some pertinent analysis struck me with a realization I wrote up at New York:

Ever since the results of the 2022 midterm elections became clear, it’s been a bit of a struggle to find a proper precedent. Yes, there have been a few past midterms where the party controlling the White House gained House seats (or just lost a few), but invariably that happened under presidents quite a bit more popular than Joe Biden, and usually in economic circumstances a lot more positive than those prevailing today. Still, the results weren’t all that crazy; Republicans did, after all, flip the House, and Democratic success in the Senate (much like Republican success in 2018) was heavily dependent on a favorable mix of contests.

The shock and awe that accompanied a relatively strong Democratic performance may have been because many were expecting a late Republican surge. The polls, after all, were pretty accurate. But it was hard for a lot of analysts from both parties to overcome the belief that the party opposing the White House would get all the late breaks and win most of the really close races. That wasn’t just a hunch; it used to be a political-science truism until late surges cemented the reelections of George W. Bush in 2004 and Barack Obama in 2012. It seemed even more probable in 2022 given the historical unlikelihood of a good Democratic midterm and the suspicion that the energy Democrats got from the Dobbs abortion rights backlash might have dissipated by November.

But that’s not how it turned out, as the Cook Political Report’s Amy Walter explains in a new analysis:

“Since 2006, the final House and Senate races we’ve rated as Toss-Ups have broken decisively in one direction. What was different about this cycle, however, is that both the House (69 percent) and Senate (currently 75 percent), broke for the White House party.”

Republicans in 2014 and Democrats in 2006 won sizable majorities of the toss-up House and Senate races. And Democrats won a majority of toss-up Senate races in 2010, as did Republicans in 2018, thanks to Senate landscapes that tilted the playing field (along with non-toss-up contests that flipped seats). So a late-breaking surge (against expectations, at least) for the White House party in both House and Senate races in a midterm truly is unusual. That Democrats also won four of five gubernatorial races identified as toss-ups by Cook reinforces the surprising late trend.

So what’s the explanation? That’s not so easy to determine. Take your pick among such factors as bad GOP candidate selection (though it wasn’t just “bad candidates” who lost), Republican extremism, or a stronger “Dobbs effect” than expected. Or, to cite the explanation that makes the most sense to me (and to Walter, who has written about “calcified” politics), maybe we are in an era where polarization and partisan attachments are so strong that midterm “swings” are less powerful and the party controlling the White House is going to be on stronger ground for the time being. As always, we’ll need more elections to supply the data needed to make postelection surprises less … surprising.