Supreme Court justices aren't fools. They know the public hangs on their every word, trying to figure out which way they will vote on a particular issue. What they say in arguments does not always match what they say in their opinions.

With that caveat brushed aside, here's what court watchers will pore over during the next few days.

First of all, Solicitor General Donald Verrilli, the government's lawyer, who spent 90 minutes arguing yesterday in favor of the health care law, came out of the gate today in a very halting fashion. He seemed repetitive at times and hoarse.

He was quickly barraged with questions from the conservative justices.

Justice Anthony Kennedy set the tone: Can you create commerce in order to regulate it?

Chief Justice Roberts: So can the government require you to buy a cell phone?

Justice Samuel Alito: Do you think there is a market for burial services?

Justice Antonin Scalia: If the government can do this, what else can it not do?

Such questions would send a veteran Solicitor General racing for a carafe of water. But Verrilli, while an experienced appellate lawyer, is only in the middle of his first term at the high court.

Kennedy, known as the swing vote on some issues in the court, asked the government a hard question: "Here the government is saying that the federal government has a duty to tell the individual citizen that it must act, and that is different from what we have in previous cases and that changes the relationship of the federal government to the individual in a very fundamental way." Not a good sign for supporters of the law.

But at times Kennedy was receptive to the government's argument. Regarding people who choose not to buy health insurance who might still be affecting the economy: "But they are in the market in the sense that they are creating a risk that the market must account for."

At the end of the day's argument Kennedy seemed skeptical of the government's argument that the health care market is unique from other markets. He said, "And the government tells us that's because the insurance market is unique. And in the next case, it'll say the next market is unique." But he did recognize a major point of the government's: that a "young person who is uninsured" will affect the rates of insurance in the health care market, in a way that might not be true in other markets. On that point he said, "That's my concern in this case."

Roberts was concerned with that limiting principle. "But once we say that there is a market and Congress can require people to participate in it … it seems to me that we can't say there are limitations on what Congress can do under its commerce power, just like any other area - given significance deference that we accord to Congress in this area, all bets are off.."

But when Michael Carvin, representing a small business group opposed to the health care law, characterized the government's argument in a way Roberts didn't like, he was quick to jump in.

"I don't think you're addressing their main point, which is that they are not creating commerce in health care. It's already there, and we are all going to need some kind of health care; most of us will at some point."

If supporters of the law thought they might be able to sway Scalia today, it wasn't evident in his questions and comments.

"You know, I'm in any market at all, my failure to purchase something in that market subjects me to regulation? "And Scalia was the first to utter the B-Word. "Could you define the market - everybody has to buy food sooner or later, so you define the market as food, therefore, everybody's in the market, therefore you can make people buy broccoli."

When Verrilli began to justify the law under Congress' power to tax and spend, Scalia shot back, " Is it a tax or not a tax? The President didn't think it was."

Alito asked at one point, " Could you express your limiting principles as succinctly as possible?" Bad sign made worse when the government's answer was not succinct.

As for Justice Clarence Thomas, he is the only Justice on the bench who has so far not participated in oral arguments by asking a question or making a comment. But he hasn't asked a question for 6 years. He is expected to vote against the law.

Justice Ruth Bader Ginsburg was the strongest voice in support of the law, and there was no indication that the three other liberal justices would vote against the mandate. At one point Ginsburg came to Verrilli's aid. "I thought a major, major point of your argument was that the people who don't participate in this market are making it much more expensive for the people that do."

Assuming the four justices appointed by Democratic presidents vote to uphold mandate, at least one of the more conservative justices must vote with them in order for the mandate to survive. Today, especially during the government's argument, that one vote did not seem clear.

"Today certainly didn't go as well as the government would have hoped, "said Stephen I. Vladeck, Professor of Law at American University Washington College of Law. "But there's a reason why we don't count votes at the end of oral arguments. And indeed there's plenty of history to suggest that even though the justices at this moment are leaning toward striking it down, there's not a guarantee that where they are today is where they'll be in June.

"Sometimes oral arguments are as much about convincing yourself that the other side is wrong as it is about convincing yourself that your side is right."