Republicans have long sought to limit abortion, both at the state and national level. But abortion opponents have stepped up their efforts in 2019, according to advocates on both sides of the issue. Alabama this week enacted a law that bans all abortions except to save a woman’s life. There would be no exceptions for pregnancies caused by incest or rape, and conducting an abortion could result in a prison sentence of up to 99 years. Four other states — Georgia, Kentucky, Mississippi and Ohio — have adopted laws that ban abortions after a fetal heartbeat can be detected, which can be as early as six weeks into a pregnancy.

What’s behind this latest push? There have been three important shifts in U.S. politics.

The appointment of Brett Kavanaugh to the U.S. Supreme Court

This may be the most significant shift.

In two high-profile Supreme Court rulings, Justice Anthony Kennedy, who was succeeded by Brett Kavanaugh in 2018, was part of a five-justice majority that struck down state laws intended to limit access to abortion. His role in those decisions left abortion opponents with the impression that Kennedy would never vote to overturn the court’s landmark 1973 Roe v. Wade decision, which holds that a woman has the right to an abortion up to the point where her fetus could live outside of the womb (generally defined as between 24 and 28 weeks into the pregnancy). Kennedy’s views on abortion, among other issues, had long held sway over the court because he was often one of the swing justices.

By the standards of previous Supreme Court rulings, the recently enacted heartbeat laws and Alabama’s ban would probably be struck down as unconstitutional. (In fact, lower courts have already ruled against the law adopted this year in Kentucky and similar provisions previously adopted in Iowa and North Dakota.)

But Kavanaugh is generally considered more conservative than his predecessor, and he might be more willing to uphold abortion restrictions or even vote to overturn Roe. (Indeed, the key justice to watch on abortion may not be Kavanaugh but Chief Justice John Roberts, who has indicated wariness about overturning Supreme Court precedents like Roe.)

So some conservatives are hoping that the new state laws will reach the Supreme Court and trigger a ruling in which the court’s five Republican appointees either formally overturn Roe or de facto overturn it by upholding measures that place limits on abortion access much earlier than 24-28 weeks, like the heartbeat bill.

“What I’m trying to do here is get this case in front of the Supreme Court so Roe v. Wade can be overturned,” Republican Alabama state Rep. Terri Collins, who sponsored the abortion ban legislation, said in an interview with The Washington Post.

The Kennedy-to-Kavanaugh swap is not the only change in the courts that could be emboldening conservatives. President Trump has appointed dozens of federal judges at the district court and appellate levels. And if these lower-level judges uphold sweeping abortion limits, they could effectively force the issue onto the Supreme Court docket.

In short, conservatives are betting that with five current justices who are all more conservative than Kennedy was, the Supreme Court will be more willing to leave abortion limits in place.

Kavanaugh likely isn’t the only factor behind the current anti-abortion push, though. I’d also point to …

The rise of one-party-rule states

The five states that have passed major anti-abortion laws this year are places where Trump won in 2016 and that are run by a GOP “trifecta” — the governor’s office and both houses of the state legislature are controlled by Republicans. More and more states these days are entirely controlled by one party or the other, and it’s not surprising that the anti-abortion movement is strongest in red states — the major government levers are controlled by Republicans, and residents are more supportive of anti-abortion measures there.

A majority of people in Alabama (58 percent), Kentucky (57 percent) and Mississippi (59 percent) said they thought abortion should be “illegal in all or most cases,” according to Pew Research Center polling from 2014. (That said, polling by the Public Religion Research Institute the same year found that just 26 percent of Alabama residents said abortion should be illegal “in all cases,” so the state’s decision to essentially ban abortion may not be as popular there.)

In Georgia and Ohio, according to the Pew poll, voters were about equally split between those who thought abortion should be legal in all or most cases and those who thought it should be illegal in all or most cases. In recent polls, pluralities of voters in both states said they opposed the heartbeat bills. And Georgia’s government has aggressively courted entertainment companies to produce movies and TV shows in the state, but that effort could be endangered by the anti-abortion legislation, with some actors and directors who support abortion rights saying that they no longer want to participate in projects in Georgia. Before 2018, those conditions were enough to stop these kinds of laws short of being enacted. Georgia’s previous governor, Republican Nathan Deal, had been wary of legislation that would turn off corporate America. Republican John Kasich, Ohio’s previous governor, twice vetoed heartbeat legislation, although he enacted a number of other abortion limits.

But in the 2018 GOP primaries to replace Deal and Kasich (neither could run again because of term limits), Ohio’s Mike DeWine and Georgia’s Brian Kemp pledged to sign strong abortion limits into law if they were elected. These pledges helped both candidates establish their conservative bona fides as they faced intra-party rivals. And after winning the general election, both Dewine and Kemp followed through on their campaign trail promises by enacting the heartbeat bills.

Republicans aren’t that worried about a backlash

You’ve heard all about how in 2018, Republicans lost the U.S. House, many state legislative races and key gubernatorial contests in part because of bad showings in suburbs and among voters with college degrees, women and younger voters. The flip side of that is the Republicans who managed to be elected anyway are not beholden to those constituencies, some of which — better-educated and younger voters, for example — tend to be more supportive of a woman’s ability to get an abortion if she chooses. (There is not really a gender gap on abortion views.)

For example, in 2014, Deal and Kasich won in part because they did pretty well in the suburbs. But DeWine and Kemp relied more on huge margins in rural areas, where voters are less likely to be college-educated (and are therefore more likely to be against abortion). As a result, DeWine and Kemp — and Republicans more generally — have fewer electoral reasons to think about voters who are in favor of allowing women to have abortions. About a third of Republican voters say abortion should be legal in all or most cases, but this bloc has virtually no power in the party’s politics. Indeed, there is no real force within the GOP to counter the well-organized anti-abortion movement. And that movement is powerful.

Marquette University political scientist Philip Rocco, who studies state politics, said he doubted that Republicans are pushing forward on abortion limits because the party’s rank-and-file voters are demanding it. Instead, he likened it to the party’s opposition to expanding Medicaid at the state level — conservative activist groups are setting the agenda for state legislators and governors in these states.

“The right has very mobilized groups who are leveraging Republican-controlled state legislatures to push abortion limits through,” Rocco said.