Tuesday Was Great for Democrats. It Doesn’t Change the Outlook for 2024.

Almost every Tuesday election since the Supreme Court’s decision to overturn Roe v. Wade has brought good news for Democrats.

Last night was no exception.

Abortion rights and marijuana legalization prevailed in Ohio. Democrats held the governor’s mansion in Kentucky, took full control of the State Legislature in Virginia and won a Supreme Court election in Pennsylvania. They even were competitive in Mississippi.

In one sense, the results were no surprise. The polls showed Democrats and their causes ahead in these races, and the party has excelled in low-turnout special elections over the last year.

But the results were especially elating for Democrats against the backdrop of the latest polls, including the newest New York Times/Siena College poll, which seemed to spell doom for the Democrats. There was no doom Tuesday night.

To many, the contradiction between Democrats’ success at the ballot box and their struggles in surveys seems to suggest the polling can’t be right.

It’s an understandable response — but it’s probably wrong.

There’s no contradiction between the polling and Tuesday’s election results. There’s not even a contradiction between the polling and the last year of special elections.

Put simply: Tuesday’s results don’t change the picture for President Biden heading into 2024.

The polls and the election results are surprisingly easy to reconcile. The surveys show millions of voters who dislike Mr. Biden but remain receptive to other Democrats and support liberal causes. The polls also show Democrats with particular strength among the most highly engaged voters, who dominate low-turnout elections like Tuesday’s, while Mr. Trump shows his greatest strength among the less engaged voters who turn out only in presidential races.

As a result, the same data showing Mr. Biden in jeopardy is entirely consistent with Democratic strength Tuesday. The fact that many of the voters he will need are now supporting other Democrats and liberal causes, as they did Tuesday, may ultimately be exactly what allows Mr. Biden to win in the end. But it doesn’t mean his political position is secure. If anything, his weakness among even these voters reveals the extent of his liabilities.

The crossover vote

The polls showed the Democrat winning Kentucky. They showed abortion rights and marijuana legalization prevailing in Ohio — and showed them to be popular in many red states all over the country. They also show that voters disapprove of Mr. Biden and that Mr. Trump leads in the battleground states.

The same data showing Mr. Biden faring terribly also shows popular support for abortion rights. They also show other Democrats faring much better than him. This doesn’t prove that the polls are right about Mr. Biden’s weakness, but if the polls were right about Ohio, Kentucky and elsewhere, perhaps they’re right about the president as well.

Tuesday night’s Ohio exit poll was a good example. Mr. Biden had a 39 percent approval rating among the voters who made abortion and marijuana legal in the state. Only 25 percent said he should even run for re-election, less than the 35 percent who said the same for Mr. Trump.

Similarly, the Times/Siena polls nailed the Democratic victories in the Senate battlegrounds last fall, but they also showed Mr. Biden with a 39 percent approval rating. Last week, we had him at 38 percent across the same four states. If the polls were right about the Senate, perhaps they’re right about Mr. Biden’s anemic standing as well.

Before moving on, it’s worth dwelling on how surprising the latest election results might be if we didn’t have the hard election vote tallies to prove it. Abortion rights winning in red states? A Democratic governor winning re-election in Kentucky? It might seem quite unlikely or at least far from guaranteed. But it was all in the polling — and so is Mr. Biden’s weakness among young and nonwhite voters.

The turnout

A second factor is that Democrats appear to have an advantage among the most highly engaged voters, who make up the preponderance of the electorate in a special election, a midterm or an off-year general election.

This is partly because Democrats have made steady gains among college-educated, older and white voters, who tend to vote more regularly than young, nonwhite and working-class voters. It’s also partly because Democrats enjoy a turnout advantage beyond demographics, as the party’s activist base has been highly motivated to defend abortion rights, democracy and defeat Mr. Trump, dating all the way to the aftermath of his victory in 2016.

As I noted last week, Times/Siena polling shows Mr. Biden leading among regular voters — the kinds who vote in primaries and midterms — but trailing among registered voters who don’t vote in those elections. The same split was evident in the latest Times/Siena battleground polls. Mr. Biden led by two points among previous primary voters and one point among those who voted in the midterms. He trailed by double digits among everyone else.

These kind of high-turnout party members aren’t ordinary Democrats — they’re very loyal Democrats. Many disapprove of Mr. Biden, but they’re ideologically consistent liberals and they’re vehemently against Mr. Trump. The same cannot be said for lower-turnout voters — including less engaged Democrats, nonwhite voters, and so on — who aren’t so ideological, and whose dissatisfaction with Mr. Biden could yield a very different outcome. It certainly does in the polling right now.

This Democratic advantage in low-turnout elections is a big deal. It probably explains the entire Democratic overperformance in special elections over the last year, based on an analysis of the nearly two dozen special elections with sufficient data for analysis, using a combination of Times/Siena polling and records from L2, a voter file vendor.

The Ohio exit poll offers yet another piece of evidence: Self-reported Biden voters outnumbered Trump voters by two points, even in a state Mr. Trump won by eight points.

Next fall, this Democratic turnout advantage will do a lot less to help Mr. Biden and Democrats. To be clear, it should help: In a close race, it might offer a narrow path to a Biden victory, especially in the relatively old, white, Midwestern battleground states. But millions of irregular voters will return to the polls, even though they have made up a sliver of the electorate in recent special and off-year elections.

Today, these less engaged voters are expressing very different attitudes from superficially similar highly engaged voters. They’re so dissatisfied with Mr. Biden that many of them tell pollsters they’ll back Mr. Trump. Others probably just wouldn’t vote if the election were held today. Either way, the presidential electorate would be significantly worse for Democrats than the one they’ve learned to love on nearly every Tuesday night.

The great question for the next year is whether these less engaged, less ideological, disaffected, young and nonwhite voters who don’t like Mr. Biden will return to his side once the campaign gets underway. The optimistic case for Mr. Biden centers on their disengagement: Perhaps he’ll win them back once the campaign reminds them of the stakes. The issues that powered Democratic strength Tuesday, like abortion, will be a central part of how he hopes to do so.

But these voters aren’t just disengaged, they’re also nonideological and disaffected. The issues that animate more regular voters, like abortion, might not be assured to win over these voters. Almost by definition, the two million Ohio voters who didn’t turn out Tuesday but who probably will next November aren’t the ones especially motivated by abortion, even if they support abortion rights in a poll. Instead, they might vote on pocketbook issues like the economy or on Mr. Biden’s age.

Either way, Mr. Biden’s path to re-election hinges on whether he can persuade these disaffected, less ideological voters to return to his side and then to turn out in his favor. Nothing about Tuesday’s results suggest this will be any easier.