The Supreme Court announced earlier this week that it will review a major abortion case, and the left has already begun to shiver. The ACLU, which can no longer be bothered to defend freedom of speech, warned that a fundamental American right is at stake. Congressman Adam Schiff, who spent the better part of four years trying to impeach an elected president, declared that Roe v. Wade is “settled.”

There is no legal regime on earth, no statute or clause, that is so supreme in the progressive imagination as Roe. The First Amendment is to be curtailed by Twitter mobs shouting “racism!” in a crowded theater, the Second Amendment is a dusty artifact from the age of flintlocks and powdered wigs, but a 1973 court ruling is absolutely unassailable. Roe is constitutional law; Roe is common law; Roe was engraved on tablets of stone and handed down by God to Jessica Valenti atop Mount Choice.

Still, progressives are right about this much: this very well could be the end of Roe v. Wade.

The case in question, Dobbs v. Jackson Women’s Health Organization, is being litigated over a statute in Mississippi that bans most abortions after 15 weeks of pregnancy. This is clearly not allowed under the half-assed scheme devised by the Court in Roe, which requires that abortions be legal until fetal viability, the point when the fetus can ostensibly survive outside the womb, around 24 weeks in. Such a line has always been arbitrary both because of its inherent judicial God-playing and because viability necessarily shifts earlier as medical technology advances. Mississippi, in crossing that line, was always aiming to land before the Supreme Court. And after their law was struck down by a district court and then by the Fifth Circuit Court of Appeals, they made it.

The last time the Supreme Court took a hard look at abortion was last summer when it blocked a pro-life law in Louisiana that would have required abortion providers to have admitting privileges at local hospitals. That was a 5-4 decision with Chief Justice John Roberts joining the five. Roberts had previously voted with the minority to uphold an almost identical Texas statute, but that was before Neil Gorsuch and Brett Kavanaugh joined the Court and gave the so-called conservatives a majority. Faced with the prospect of actually influencing abortion law, Roberts headed for the hills. He cited the precedent of the Texas case—which he opposed—as a reason not to intervene in the Louisiana one.

Roberts was once regarded as a conservative legal golden boy, so much so that George W. Bush nominated him to be chief justice before he was even on the Court. Today, he’s seen as too addled by political concerns and stare decisis to do what’s right. Yet the Court has also changed since he last sold out. Amy Coney Barrett now sits enthroned in all her splendor. That means conservatives can get to five votes without Roberts. Gorsuch, who takes a less restrained approach to precedent than the light-fingered chief justice, has even been low-key quarreling with Roberts in his opinions, a sign of the former tiebreaker’s diminished power.

There is something to like in Roberts’ incrementalist view of the bench, even if it occasionally leads to the wrong outcomes. But the fact remains that the only way to roll back compulsory legal abortion will be through an act of Court audacity. And the dirty little secret of conservative judicial politics is this: it’s always been about Roe. No volunteer canvasser has ever showed up at a Republican presidential campaign HQ, rubbing his hands together, gushing, “Think of it! One more justice and we can finally get rid of the Chevron Doctrine!” That’s not how this works. For the door knockers and the envelope lickers, judicial confirmations are code for abortion. And given that pro-choice activists once tried to smear Anthony Kennedy as being too pro-life to sit on the Court, it seems fair to surmise that the left thinks the same way.

The judicial jostling has always been a culture war, and now it may have finally paid off. Picture that “But Gorsuch” meme only the sign is about 200 feet above the water. The Mississippi case is the big one, and it may also be the last one. If the Court doesn’t do the deed now—if one of the conservative justices wobbles and saves Roe—then it’s difficult to imagine that it willl ever get done. I suppose Justice Stephen Breyer, 82, could end up leaving or passing away under a Republican president (progressives are already screaming for him to retire), which would allow for the appointment of yet another conservative justice. But lightning struck thrice under Donald Trump (well, twice); it seems unlikely to strike again. And let’s not forget that Clarence Thomas, though 10 years younger than Breyer, is also getting up there in years.

This strategy eventually runs out of time, not just because the justices age but because Roe does as well. Pro-lifers are well aware of the admonition that if you don’t overturn a court decision within 20 years, you never will. And Roe long ago passed that milestone. This dovetails into another set of stakes in the Mississippi case, which have to do with internecine conservative politics. There are some on the right who have despaired of this achingly slow strategy, measured not just in years but in human lives. They’ve grown suspicious of the Federalist Society, or FedSoc, the legal group that grooms conservative court nominees. They worry FedSoc is too establishment and not focused enough on social issues like abortion.

This has resulted in challenges to FedSoc’s regnant judicial philosophy of originalism, most notably from the legal scholar Josh Hammer who is working on an alternative called “common good originalism.” What hasn’t been proposed is a practical strategy to overturn Roe that doesn’t involve waiting on the current Court. The skeptics thus haven’t parted ways with the right-of-center legal movement—not yet—but a misfire in the Mississippi case could cause them to reevaluate. They’re already annoyed over what they view as Gorsuch’s betrayal in Bostock v. Clayton County, which saw him peer into the Civil Rights Act of 1964 and magically discover that its anti-discrimination protections on the basis of “sex” also covered gay people and the transgendered. All this from a textualist, an originalist—hence the skepticism.

Yet ironically, it’s that same assertiveness in Bostock that makes Gorsuch more likely than Roberts to throw out Roe…even though Roberts agreed with Gorsuch in Bostock…yet didn’t agree with him on last year’s abortion case. It’s like herding cats, this. Jurists are not party-line legislators, and treating them as such long ago grew frustrating. Will it pay off? The Court says that in taking the Mississippi case it intends to answer the question of “whether all pre-viability prohibitions on elective abortion are unconstitutional.” It’s possible they could simply agree with Mississippi and move the viability line established in Roe back to 15 weeks in accordance with that state’s law.

Yet remember how brittle that line is. Over at First Things, the law professor Gerard Bradley argues that “the main arguments offered by Mississippi against ‘viability’…work as well against a fifteen-week ‘viability’ line as they do against one set at twenty-two weeks.” And from there, Bradley adds, “The court will struggle, and perhaps mightily, to write an opinion that discards ‘viability’ without overturning Roe.”

Roberts might be willing to thread one of those needles. But the other five? If Bradley is right, then it’s all or nothing. This is the big one and the stakes are eye-wateringly high.