On Tuesday, we got our first test of how potent an issue abortion might be for Democrats this fall. In a state that overwhelmingly voted for then-President Donald Trump in 2020, a ballot initiative clarifying that Kansas’s state constitution does in fact protect abortion won by double digits.

What’s going on?

On the one hand, public opinion on whether abortions should generally be legal or illegal hasn’t changed much since the Supreme Court decided in Dobbs v. Jackson Women’s Health Organization to end the constitutional right to abortion earlier this summer. In fact, daily tracking polls from Civiqs show that the share of registered voters who think abortion should be legal has held steady at 57-58 percent throughout the past year — even though there have been mounting restrictions on reproductive rights.

But the relative stability of the topline numbers masks significant changes in the scenarios under which Democrats, independents and Republicans now think that abortion should be permitted or banned — shifts that speak in part to why abortion is becoming such a powerful wedge issue for the Democratic Party. 

For starters, there is evidence that Democrats are gravitating toward supporting unfettered abortion rights. In the chart below, you can see that Democrats polled by Civiqs were once evenly divided over whether abortion should be legal in all or most circumstances. But Democrats who think abortion should always be legal now outnumber their counterparts who say it should be mostly legal by a nearly two-to-one margin (59 percent to 32 percent).

The same uptick appears in a slightly different question from weekly tracking surveys by YouGov/The Economist. Shortly before a draft of the Dobbs decision was leaked and obtained by Politico in early May, only 42 percent of voters who cast their ballots for President Biden in 2020 agreed with the following statement: “Abortion should always be legal. There should be no restrictions on abortion.”

The April 9-12 survey was the last time YouGov/The Economist asked about the scenarios in which abortion should be legal or illegal before the leaked decision on Dobbs was published on May 2.

” data-footnote-id=”1″ href=”http://fivethirtyeight.com/#fn-1″>1 But that share has now grown to between 49 percent and 54 percent in all six of the surveys YouGov/The Economist conducted since the Supreme Court overturned Roe v. Wade.

It’s not just Democrats either. Independents are also moving toward supporting unrestricted abortion access. The share of unaffiliated voters who think abortion should be legal in all cases has increased by 5 percentage points over the past year in Civiqs’s daily tracking poll, while the data from YouGov/The Economist reveals an even sharper surge. Just 17 percent of independents thought there should be no restrictions on abortion in the April 9-12 YouGov/The Economist poll, but in the six weekly surveys they conducted since Dobbs became the law of the land, that number among independents has climbed to an average of 29 percent.      

Meanwhile, there isn’t a huge shift in the share of Republicans saying abortion should be legal in all circumstances, but they are increasingly likely to say that abortion should be legal in most circumstances. What’s more, the share of Republicans who said abortion should be illegal in all cases has decreased from 24 percent in February to a record low of 18 percent in Civiqs’s daily tracking poll. That said, a majority of Republicans, 59 percent, still think abortion should be illegal in most cases.    

Overall, though, the shift in attitudes on abortion post-Dobbs increasingly favors Democrats. Indeed, one reason abortion is becoming such a potent wedge issue for the party is that it increasingly unites its base, and independents are also closer to Democrats on this issue than Republicans, as you can see in the chart below.

A bubble chart showing the share of Democrats, independents and Republicans who believe one of four stances on abortion: It should be legal in all cases, legal in most cases, illegal in most cases or illegal in all cases.
A bubble chart showing the share of Democrats, independents and Republicans who believe one of four stances on abortion: It should be legal in all cases, legal in most cases, illegal in most cases or illegal in all cases.

Even in a dark-red state like Kansas, far more registered voters support abortion always being legal than support it always being illegal (by 25 percent to 11 percent, respectively, in Civiqs’s state polling data). That’s presumably, in part, at least one reason why the Kansas ballot initiative that tried to open a pathway to restricting abortions in the state was decisively defeated on Tuesday.

The fact that Democrats are also now more likely than Republicans to rate abortion as an important issue is a big factor here, too, that’s working in the Democrats’ favor. Up until recently, Republicans were more likely than Democrats to rate abortion as a “very important” issue. This abruptly changed, though, after the Supreme Court decided not to block Texas’s abortion law that banned most abortions once an ultrasound could detect cardiac activity, usually about six weeks into a pregnancy, from taking effect on Sept. 1, 2021.

In fact, the chart below shows that since then, Democratic voters have consistently rated abortion as more important than GOP voters have. The share of Biden and Trump voters who think abortion is “very important” has diverged even more sharply after both the Dobbs leak in early May and the Supreme Court’s subsequent decision in late June — so much so that Biden voters are now over 20 points more likely than Trump voters to say that abortion is “very important.”

These results are consistent with a long line of political science research that shows how threats and anger are often more motivating when it comes to people taking political action. They also dovetail nicely with more recent research on how the public reacts negatively to changes to the status quo. In fact, negative reactions to unpopular policy changes may have even affected two of the past three midterm-election outcomes, as threats to the health care status quo helped Democrats in 2018 and hurt them back in 2010. 

Abortion has all the elements, then, of a particularly potent wedge issue for the Democratic Party. Democrats are increasingly unified and motivated to return to the status quo of legal abortions under Roe — a constitutional right that most Americans had long taken for granted. Republicans, meanwhile, are more divided and demobilized by an issue that has historically rallied its base. And independents are closer to Democrats on abortion, especially in states where Republican lawmakers have passed overwhelmingly unpopular abortion bans without exceptions for rape and incest.   

To be sure, none of this changes the fact that Democrats face an uphill battle in November. Republicans, after all, are still a heavy favorite to win a majority of seats in the House. Yet, as FiveThirtyEight editor-and-chief Nate Silver wrote last week, the political environment for Democrats has improved since the Dobbs decision. And that might mitigate the landslide midterm losses normally expected from a congressional majority weighed down by negative economic growth and the unprecedented disapproval of the incumbent party’s president at this point in his term. Regardless of this year’s election outcomes, though, the trends above clearly suggest that abortion will continue to be an effective wedge issue for the Democratic Party moving forward.

Michael Tesler is a professor of political science at University of California, Irvine, author of “Post-Racial or Most-Racial? Race and Politics in the Obama Era” and co-author of “Identity Crisis: The 2016 Presidential Campaign and the Battle for the Meaning of America.”