Thread by @SCOTUSblog

Oral argument in California v. Texas -- the constitutional challenge to the ACA -- is about to begin. It's set for 80 minutes of argument time (but likely will go longer). You can listen live on C-SPAN: c-span.org/video/?471185-….

Follow this thread for live updates.

Arguing first is Michael Mongan, the solicitor general of California (which, along with other blue states, is defending the ACA). He says that, even if the court holds the mandate unconstitutional, Congress' intent is that the rest of the law should remain intact.

Chief Justice Roberts is the first to ask questions. He starts with the issue of standing (i.e., whether the challengers have the legal right to bring this suit). If the court finds no standing, it would avoid having to reach merits of the challenge.

Justice Thomas says that many states' mask mandates during the pandemic don't have a penalty for non-compliance -- he suggests that might be analogous to the penalty-less mandate in the ACA. Thomas asks: Would someone have standing to challenge a mask mandate?

Justice Breyer also asks about standing. Mongan says the Trump administration (which is arguing against the ACA) has advanced a "very novel" concept of legal standing that would allow litigants to challenge provisions of laws even when they aren't harmed by those provisions.

Justice Alito asks about standing, too. He suggests that the Republican-led states may have standing because the ACA forces them to take certain actions in their Medicaid programs -- thus increasing costs for the states and providing a legally cognizable injury.

Justice Sotomayor responds to Alito. She says that if the states are injured by the ACA's Medicaid provisions, they should bring a challenge to those specific provisions -- not try to invalidate the entire law through a backdoor challenge to the individual mandate.

The court is clearly very focused on the standing issue. Justice Kagan asks Mongan to respond to the arguments that the GOP-led states have standing to challenge the law, as well as the arguments that two individual plaintiffs have standing.

Justice Gorsuch suggests that, even though the individual mandate no longer has a penalty attached, the federal government could still bring a civil action to enforce compliance with the mandate. Mongan says no, he doesn't think the government could do that.

Justice Kavanaugh asks: If the government passed a law requiring all homeowners to purchase and fly an American flag in their front yards, but the law has no penalty for non-compliance, would individuals have standing to challenge that law?

Justice Barrett: What should we make of the fact that Congress didn't formally repeal the individual mandate's penalty? Mongan responds that Congress conceived of the "mandate" provision as a choice: either buy insurance, or pay the penalty (which is now $0).

Mongan, wrapping up his argument, says that striking down the entire law would "do violence" to Congress' intent, because Congress never thought that eliminating the penalty would jeopardize the entire law.

Now up at the virtual lectern: Don Verrilli, the former solicitor general under Obama, who successfully defended the first constitutional challenge to the ACA (NFIB v. Sebelius) in 2012. This time around, Verrilli is defending the law on behalf of the U.S. House.

Roberts leads off the questions for Verrilli by noting that, when Congress first passed the ACA, it thought the individual mandate was a linchpin of the law. That was the whole premise of NFIB, he says to Verrilli. "We spent all of that time talking about broccoli for nothing?"

Thomas picks up on the same theme, asking Verrilli why the court shouldn't view the mandate provision as central to the ACA (and thus potentially not severable from the rest of the law).

Telephonic SCOTUS arguments are not free of glitches -- Breyer begins his questioning but isn't sure if his audio is connected. Then, shortly after Breyer starts speaking, Roberts interrupts and calls on Alito. Unclear what exactly happened there.

After Alito is done asking questions, Roberts apologizes for audio issues and returns to Breyer, who good-naturedly says no worries and passes the baton to Sotomayor.

Kagan asks Verrilli about the severability question -- in particular, a legislative finding in the ACA that the individual mandate is essential to the full law. Kagan notes that the challengers view that finding as an "inseverability clause."

Verrilli's response to Kagan: Even if that finding suggests that the 2010 Congress believed the full ACA could not function without the mandate, it's clear that the 2017 Congress (by eliminating the penalty but leaving the rest of the law untouched) did not agree.

Big comment from Kavanaugh just now: "I tend to agree with you" that the case is "very straightforward" under our severability precedents. Those precedents (including an opinion authored by Kavanaugh last term) say there is usually a strong presumption in favor of severability.

Kavanaugh could vote to declare the individual mandate unconstitutional (his questions so far suggest he thinks it it) but also vote to sever the mandate and leave the rest of the law in place. He hinted at such an approach last term in this case: scotusblog.com/case-files/cas…

Now arguing: Kyle Hawkins, the solicitor general of Texas. Texas is the lead state among a group of 18 GOP-led states challenging the law.

Roberts now suggests he, like Kavanaugh, is skeptical of the challengers' severability argument. "It's hard for you to argue," Roberts says to Hawkins, that the 2017 Congress intended for the entire ACA to fall if the individual mandate were struck down.

Maybe it's true that some lawmakers would have wanted the court to strike down the full law, but "that's not our job," Roberts says.

Roberts, like Kavanaugh, wrote an opinion last term in which he found one provision of a statute invalid but upheld the remainder of the law.

A very animated Breyer presses Hawkins on his theory that a command to do something, without a penalty, is unconstitutional. Under that theory, Breyer says, all sorts of "hortatory" statements from Congress (such as laws that encourage people to "plant a tree") would be invalid.

Kagan with a trenchant and very Kagan-like question. She notes that the 2017 Congress made the mandate LESS coercive. So "how does it make sense to say that what was not an unconstitutional command before has become an unconstitutional command now?"

Kavanaugh again giving a big signal of his thinking on severability -- this time even more strongly than before. "It does seem fairly clear that the proper remedy would be to sever the mandate provision and leave the rest of the act in place."

So far, Kavanaugh's repeated comments suggesting he is inclined to separate out the individual mandate (rather than striking down the entire ACA if the mandate is deemed unconstitutional) are the most significant development of this morning's oral argument.

Both Kavanaugh and Roberts have suggested this morning that they may view the individual mandate as severable from the rest of the law.

If those two justices join the court's three liberals in finding that the mandate is severable, that would be five votes to save the ACA.

Now arguing: Acting U.S. Solicitor General Jeffrey Wall on behalf of the Trump administration, which has joined the Republican state officials in opposing the ACA. Wall is the final advocate of the day.

Breyer with a low-key vocabulary lesson this morning. Earlier, he was asking about "hortatory" statutory provisions. Now he wants to know about "precatory" language. Breyer has lots of fancy synonyms for the concept of encouragement.

Sotomayor asks Wall an interesting hypo: If Congress had temporarily phased out the mandate penalty, and then scheduled to phase it back in in future years, would that be constitutional? Wall says yes.

Sotomayor says that shows that a zero-ed out tax can still be a tax.

Kagan says many modern laws are omnibus statutes with thousands of provisions. If any challenger can attack an entire law based on an injury from any single provision, that would "explode" the court's standing doctrine, Kagan says.

Gorsuch picks up on Kagan's concern.

Wall says there is no opening-of-the-floodgates problem because this case is atypical. Normally, Wall says, "It's going to be very hard to make out an inseverability claim that would get past the motion-to-dismiss stage."

Kavanaugh asks Wall about his argument that a congressional finding in the original ACA constitutes an "inseverability clause." Kavanaugh once again telegraphs his view on the severability question, saying there is a "strong background presumption of severability."

Wall's response to Kavanaugh: There is no "magic words" requirement for how Congress needs to indicate its view that a provision cannot be severed. Wall says the congressional finding about the essential role of the mandate is "the equivalent of a targeted inseverability clause."

Acting U.S. Solicitor General Wall wraps up his argument by telling the court that it should strike down the ACA and “allow the political branches to decide how to proceed, given the peculiar circumstances of this moment.”

In a brief rebuttal, California's SG highlights the ACA's broad impact on the health care of hundreds of millions of Americans. If Congress' "surgical amendment" to the mandate created constitutional problems, he says, the proper remedy is to leave the rest of the law in place.

That's a wrap for the Obamacare argument. At 5 p.m. eastern, we'll be hosting a special "happy hour" live video chat right here on Twitter. SCOTUSblog publisher Tom Goldstein, reporter @AHoweBlogger, and Professor @AbbeGluck will share their reactions and answer reader questions.