On Tuesday last week, after conservative justices put Solicitor General Donald Verrilli through the ringer, Toobin's snap reaction was apocalyptic. He called the arguments a "train wreck" for the Obama administration and set the odds low: "If I had to bet today, I would bet that this court is going to strike down the individual mandate," he said.
Toobin is a writer for the New Yorker, a CNN analyst and author of the forthcoming book, "The Oath: The Obama White House vs. the Supreme Court," due out in September. His commentary is widely respected, and so, predictably, his ominous reading of the justices shifted headline writers into overdrive, and sent the law's supporters and detractors into fits and spasms of very different kinds.
But as uneasy as he is with the scrutiny that attends his big prediction, Toobin stands by his take.
"In my experience when the argument goes badly for one side, that side generally loses," Toobin said. "That's not obviously a 100 percent guarantee [but] my view of oral argument is based on watching oral arguments change at the Supreme Court over the years."
The problem for the Obama administration, Toobin said, is a Rehnquist-era custom whereby the justices typically don't attempt to sway one another away from public scrutiny. That means oral arguments are the one place where justices can swing one another's votes, if advocates like Verrilli fail to convince.
"Rehnquist set up a social system at the court where he believed good fences made good neighbors," Toobin said. "The justices did not interact with each other about their work in great detail."
Chief Justice John Roberts has sustained that policy, which means that last week's oral arguments were a huge missed opportunity.
"Oral arguments are the only time they are a captive audience to each other," Toobin said. "They don't lobby each other in their offices, but they do lobby each other in oral arguments."
That means there's less posturing from the bench than most court-watchers might think -- because their window to convince their peers is so limited.
"By and large, you don't hear them playing devil's advocate, because that would be a waste of their time in front of their captive audience," Toobin said.
So when five conservative justices (or four conservative justices and the silent but consistent Clarence Thomas) signal distaste for a provision of law behind the dais, that provision's in trouble.
The challengers' case, however, is very fragile. It requires a majority of justices to believe that the individual mandate stands completely apart from the tax penalty that will enforce it; and that the idea behind it is to regulate not the market for health care services, in which nearly everyone is a participant, but narrowly the market for health insurance, which millions of people choose to avoid. If either argument falls, the case begins taking on water quickly. Roberts and Justice Anthony Kennedy both appeared hostile, at times, to the challengers' logic.
Toobin acknowledged the importance of those moments. But if conservative justices' broader antipathy to the law overwhelms their true sense of the case's constitutional complexities, they might still strike it down.
"These issues are sufficiently complex and sufficiently out of layman's everyday experience, that however they write it it's not going to seem crazy or incredible to the average reader," Toobin said. "John Roberts is a really, really good writer, and whatever side he's on he's going to write a very persuasive argument. It's their Constitution, they'll write it how they want."