A federal judge expressed skepticism Wednesday that the rest of Obamacare can survive without the tax penalty that was originally the crux of the 2010 law.

U.S. District Court Judge Reed O’Connor fired stern questions at Democratic state attorneys general who are defending the law, saying the Supreme Court cast Obamacare as a package deal, with the tax penalty tethered to the law’s goodies.

“It does seem for majority of cases, the Supreme Court says to look at the original legislation as enacted. Why would I not?” Judge O’Connor, an appointee of George W. Bush, said, according to a Modern Healthcare report from the courtroom.

The judge is presiding over a high-profile lawsuit that says Congress’ decision to zero out Obamacare’s mandate penalty in 2019 means the rest of the law, including requirements that insurers cover people with preexisting conditions, must fall.

Six years ago, Chief Justice John G. Roberts Jr. cited Congress’ taxing authority in upholding the mandate, which was crafted to prod healthy people into the new marketplace.

“The Supreme Court held Obamacare was only tethered to the Constitution by a very thin thread — the fact that the individual penalty raised some revenue,” said Texas Attorney General Ken Paxton, who filed the suit with 19 other red-state officials. “Congress severed that thin thread with the tax act of 2017, and all of Obamacare must fall.”

Obamacare’s defenders, though, say Congress didn’t muster the votes to repeal the law — and the court’s shouldn’t go there.

Sen. Chris Murphy, Connecticut Democrat, said such a ruling “would be a pretty big middle finger to the legislative branch.”

Texas has asked for a preliminary injunction halting Obamacare in its tracks. Judge O’Connor did not rule from the bench in Fort Worth, though he said he would get something out as quickly as possible.

The Trump administration has sided with the states on the legal arguments, but has urged the judge to pump the brakes on a decision that would freeze Obamacare right away.

They said any changes shouldn’t happen until the start of the new year, when the mandate tax sinks to zero.

The pending lawsuit is the subject of intense scrutiny among lobbyists, Capitol Hill lawmakers and policy analysts.

It even seeped into Senate confirmation hearings Wednesday for Supreme Court nominee Brett Kavanaugh, who might hear the case if it make it through the lower courts.

Sen. Sheldon Whitehouse, Rhode Island Democrat, demanded to know if Judge Kavanaugh thought a law requiring insurers to cover people with preexisting conditions would withstand scrutiny.

Judge Kavanaugh refused to offer thought, saying those were “hypotheticals” that may come before him and it would be inappropriate to the parties to weigh in now.

Mr. Paxton, who filed the lawsuit in February, said his goal was to return power over health decisions to states and consumers.

“Texans and other Americans should be free again to make their own health care choices, including which doctor they want to see,” he said.

Some congressional Republicans, though, are worried about the consequences should he win.

Those Republicans have announced legislation to backfill Obamacare’s protections.

A Kaiser Family Foundation poll released Wednesday said three quarters of the public view Obamacare’s protections for sicker Americans as “very important,” while four in 10 are worried they or a family member will lose insurance outright if the courts rule in favor of the conservative states.