The outcomes of Supreme Court cases are notoriously difficult to predict, but that hasn't stopped some of the top legal minds in the country from venturing educated guesses as to how the high court will rule on the Affordable Care Act. The consensus among legal experts is that Chief Justice John Roberts will author the majority opinion (he hasn't written for the majority since February). But just because Roberts is conservative, doesn't mean the court will strike down the bill. Monday's decision on Arizona's immigration bill, in particular, has provided fresh fodder for forecasters. These are the tea leaves experts are reading into.

The happy-go-lucky justices. If the Supreme Court was about to side against you in a landmark case, would you be cheerful when talking about the case? The likely answer is no and that's what has conservatives worried about the behavior of two of the court's liberal justices in the last month. The dreading began in earnest when liberal Justice Ginsburg spoke at an American Constitution Society convention in a decidedly cheerful tone, joking about the amount of "press conference, prayer circles, protests and counter-protests" occurring near the court, poking fun at the Anti-Injunction Act and framing the question of the individual mandate as an issue of whether it should be "chopped like a head of broccoli." Those remarks appear at the 27:40 mark:

Similarly, at the Supreme Court last week, as apprehension over Obamacare increased, liberal Justice Elena Kagan joked while reading a case about sovereign immunity and prudential standing: "Maybe not what you’ve all come for today," as reporters erupted in laughter.

All this, of course, has had some conservative blogs mighty scared. Reflecting on Ginsburg's reaction, The Volokh Conspiracy's Orin Kerr said " she seems to be having fun talking about the case ... She jokes about the rumors concerning when the case will be handed down." Disturbingly, he speculates that "Ginsburg’s tone reflects some satisfaction with how the case came out." In sum: Is this what a justice sounds like who's about to be on the opposite side of history?

John Roberts as Majority Opinion Writer. Everyone agrees that Justice Roberts writing for the majority would be an important factor in this case but there's lots of disagreement about which way he'll rule. Some believe that Roberts will resist a 5-4 vote on Obamacare. That's why the Obama administration's legal strategy was to argue ideas sympathetic to Justice Kennedy whose vote would force Roberts to side with the liberals to avoid a polarizing 5-4 ruling that could damage the Roberts Court's legacy.

Today, on Good Morning America, ABC News' Supreme Court correspondent Terry Moran said if Roberts writes for the majority, the "tea leaves" suggest that the individual mandate will most likely fall. CNN's legal analyst Jeffrey Toobin agrees, saying Roberts writing the majority decision "would not fill me with confidence if I were in the Obama administration." He noted that Roberts “is a very conservative George W. Bush appointee who was extremely hostile to the law during oral arguments.” But not everyone sees Roberts as a staunch conservative. Obamacare critic John Eastman, a professor at the Chapman School of Law, is very worried that Roberts could infuriate conservatives.  “He’s a creature of the Washington administrative state," he told Politico. "That’s his background."

Scalia's outburst. Legal experts are also reading the tea leaves in conservative Justice Antonin Scalia's dissent on Arizona's immigration bill on Monday. His angrily-worded opposition stated that it was "mind-boggling" to declare that states can't do the job the federal government is failing to do (i.e. keep out illegals). To former Acting Solicitor General Walter Dellinger, in a commenetary for Slate, it seemed like something else was bothering Scalia. "He is being anticipatorily mad about what may happen on Thursday," he said. "You think?"

Intrade. If you believe money talks louder than anything else, then take a look at Intrade, the online trading exchange that lets you bet on future events. Right now, the betting site gives it a 79 percent chance that the individual mandate will be struck down.

Roberts on Arizona. On Monday, Justice Roberts provided more fodder for forecasters when he sided with the court's liberals on the Arizona immigration case. As The New Yorker'John Cassidy writes, that's a good sign for Obamacare. "The Arizona ruling showed, once again, that the Court’s right wing isn’t always a united phalanx," he writes. "If it were to do the same thing in the health-care case, the case law on the interstate commerce cause would mitigate against striking down Obamacare, or even just outlawing the individual mandate." Others, however, say that Arizona bears no weight on this at all. “It would be totally wrong” to assume that, said SCOTUS blog founder Tom Goldstein in an interview with Politico. “They’re very different cases. … There are overlapping themes about states’ rights, but the federal immigration power is not the same as federal commerce power.”

Oral arguments. The biggest event that spun all of this speculating into over-drive, of course, was the three days of oral arguments in March. The aggressive line of questioning in opposition to the individual mandate had a slew of legal analysts forecasting doom for the bill. "I think the individual mandate is gone, based on the questioning," said Toobin in March. "It sure looks like there are at least five votes to get rid of ... the individual mandate ...  this morning was unbelievable. It was like a given that they're throwing out the mandate. Anthony Kennedy was like, 'Well, when we throw out the mandate...' -- Do you know what a huge deal that is? It's a huge deal in American history, not in the news cycle."