On Tuesday, the Fifth Circuit Court of Appeals will hear oral arguments in Texas v. Azar, the latest in the Republican Party’s unending effort to get the courts to do what Congress wouldn’t and rip out the Affordable Care Act by its roots.

The argument here is ludicrous in its reasoning and unlikely to survive the legal process. It holds, in short, that since Congress removed the penalty from the individual mandate, the individual mandate is no longer a tax; because the individual mandate is not a tax, it is no longer constitutional; and if the mandate is no longer constitutional, the entire law must be judged unconstitutional and erased from the books.

To do anything else would be, of course, immodest. As Texas District Judge Reed O’Connor wrote in his 2018 opinion backing the case, courts “are not tasked with, nor are they suited to, policymaking.” Yes, he literally wrote that as he tried to overturn Obamacare with a stroke of his pen.

O’Connor is a former GOP Senate aide with a history of hard-right rulings on Obamacare; it’s unlikely this case will ultimately overturn the law. But the effort speaks to two larger dynamics in American politics right now. First, the GOP’s embrace of a particularly radical form of judicial activism, and second, the way in which the Republican right have become Medicare-for-all’s most important allies.

Let’s start with the legal case. “If you were ever tempted to think that right-wing judges weren’t activist — that they were only ‘enforcing the Constitution’ or ‘reading the statute’ — this will persuade you to knock it off,” wrote law professor Nicholas Bagley. “This is insanity in print, and it will not stand up on appeal.”

You might have spotted a hole in O’Connor’s reasoning: Wasn’t it Congress that chose to remove the penalty from the individual mandate without choosing to repeal all of Obamacare? And as such, isn’t it quite clear that Congress intended Obamacare to stand even without an individual mandate imposing a penalty?

Ah, but O’Connor thought of this. He said that since the Congress that repealed the individual mandate was working through budget reconciliation and couldn’t repeal the mandate, “the 2017 Congress had no intent with respect to the Individual Mandate’s severability.” (“Severability” refers to whether a provision can be severed from a law while the law still stands.) He goes on to argue that even if he’s wrong, and the 2017 Congress did intend to do what it did, what it intended to do was to leave the mandate intact but penalty-less, thus leaving it unconstitutional, thus leaving the whole law unconstitutional.

If this doesn’t make sense to you, that’s because it doesn’t make sense. Even the Trump administration initially didn’t want the judge to go this far. They asked that he simply kill the individual mandate and the protections for preexisting conditions, but leave the rest of the law standing.

But if you want to know why Democrats are dotting the landscape with new proposals for Medicare-for-all and Medicaid-for-all, this ruling is a useful artifact. The basic idea behind Obamacare was that a public-private system based on Mitt Romney’s Massachusetts reforms would command some Republican support, or at least acceptance, and thus be easier to pass and to expand.

Republicans have proven that theory wrong. Instead, the private-public construction of Obamacare has given opportunistic Republicans their most effective attacks on the bill. Those attacks have been legal, like this assault on the regulations governing private insurance purchase; and political, like the ads slamming high deductibles and complex shopping schemes and Medicare spending cuts.

If Hillary Clinton had won in 2016 and Democrats had filled Antonin Scalia’s Supreme Court seat, Obamacare would be safe, and it’s likely the party would’ve largely moved on from health care to focus on paid maternity leave, universal pre-K, or some other priority.

But with Obamacare under constant threat, Republicans have refocused Democrats on building what they failed to in 2010: a universal health care system simple enough and popular enough that it is safe from constant political and legal assault. And that means some version of Medicare-for-all.

It’s easy to look back from 2018 and wonder why Democrats didn’t just pass Medicare-for-all in 2010. I covered that fight, and the answer is that moderate Democrats, whose votes were needed, opposed a single-payer system. Sen. Joe Lieberman, for instance, refused to vote for the bill until both the public option and a proposal to open Medicare to 55-year-olds were killed, and without his vote, the legislation was dead.

But nearly a decade of constant and cynical assault on what was supposed to be a compromise bill has pushed the Democratic Party left on health care policy, and persuaded Democrats everywhere that trying to compromise or placate Republicans is foolish. The legacy of the GOP’s Obamacare repeal strategy won’t be the destruction of the Affordable Care Act but the construction of Medicare-for-all — or at least Medicare-for-more.

This is doubly true if Republicans somehow succeed in this case. Imagine a world where Judge O’Connor’s ruling is upheld. In that world, a Republican judge cuts tens of millions of people off health insurance shortly after Republicans lost a midterm election for merely trying to cut those people off health insurance, and shortly before America will choose its next president. The aftermath of that would be a political massacre for the GOP, and a straightforward mandate for Democrats to rebuild the health system along the lines they prefer.