And conservative writers including Philip Klein of the Washington Examiner and the Cato Institute’s Michael Cannon have criticized the lawsuit. The headline on Klein’s piece is: “I hate Obamacare, but Texas judge’s decision on its unconstitutionality is an assault on the rule of law.”

How has this case managed to go so far? Jonathan Cohn of HuffPost has written a helpful summary.

The brief version is: The Supreme Court ruled in 2012 that the health law was legal even though it overreached in requiring people to buy health insurance, because that requirement — known as the mandate — wasn’t really a requirement. People could choose not to have insurance and instead pay a fee, which meant that the mandate was more akin to a tax on the uninsured. Congress clearly has the right to impose taxes.

Trump’s tax law, passed in 2017, reduced this fee on the uninsured to zero. In the current lawsuit, the plaintiffs have taken advantage of this change to argue that the mandate is now back to being a mandate rather than a tax — even if it’s an irrelevant mandate, because ignoring it brings no penalty. As Cohn wrote, “It doesn’t take a fancypants law degree to see that the new scheme is, if anything, less intrusive than the old one — a point that the attorneys for California and the U.S. House [who were arguing against the Trump administration] made several times.”

And yet …

What happens next is unclear. The two Republican appointees on the appeals court, which is based in New Orleans, seemed sympathetic to the lawsuit during arguments on Tuesday. But perhaps they will nonetheless rule against the challenge.

Or perhaps the New Orleans court will rule against the law and the Supreme Court will again reaffirm its constitutionality, overruling the appeals court.