As I write this it is still possible the Democrats will lose control of Congress, with all that entails, but the Democrats did outperform the fundamentals, and it is useful to think about why. Here is my quick list of possible explanations:
Increased partisanship and decreased cross-over voting (see here).
Inflation may not be as much of an economic negative as a lot of commentary suggests; maybe unemployment matters more.
Voters may be better at separating disappointment with Biden from support for Republicans than retrospective voting models assume. It’s not just “throw the bums out” if the other party doesn’t look so hot.
Voters may be better at understanding what politicians are responsible for than retrospective voting theory suggests. Perhaps they understood that Biden was not responsible for high gas prices etc.
Dobbs. Pro-choice referenda are doing well so far.
Maybe Biden’s focus on democracy, the 9/11 hearings, and the raid at Mar-a-Lago made democracy a voting issue for a few swing voters or created more Never Trump Republicans. One suggestive piece of evidence: governor and secretary of state candidates who endorsed the big lie are not doing well, though Lake could win.
Candidate quality continues to be a problem for Republicans. The first party to convince its base voters that moderation is a virtue may reap a large electoral advantage.
Republican crime messaging may have been less effective than many hoped/feared. Very interesting.
Turnout: we still have much to learn about turnout by ideology, race, gender, etc.
This will take many months to sort out.
If the Democrats keep the Senate, winners are democracy, Democrats, Biden, moderation, Ukraine, and DeSanctimonious. Losers are Trump, Trump, Trump, Putin, Republicans, Kevin McCarthy. (Trump is lucky he chose not to announce his candidacy on Monday.) If Republicans win the Senate, it’s going to be ugly.