But Stephen Presser, professor of legal history at Northwestern University School of Law, believes the health-reform law will be ruled unconstitutional in a narrow 5-4 decision.
"I think [Justices Antonin] Scalia, [Clarence] Thomas, [Samuel] Alito and [John] Roberts will all have to view this as Congress going much too far and virtually ignoring the 10th Amendment," Presser said. "Justices [Stephen] Breyer and [Ruth Bader] Ginsburg have always been strong voices for expanded Congressional power, and Justices [Elena] Kagan and [Sonia] Sotomayor are not going to embarrass the man [Obama] who appointed them, so there are four sure votes to uphold the legislation as well. That leaves only [Anthony] Kennedy as the swing vote, as most commentators, I think, understand."
And Presser believes Kennedy will vote with the conservative justices, based on prior rulings that have argued for states' rights as the best way to preserve individual liberty. "If he follows that logic he will have to vote to overturn the ACA's individual mandate," Presser added.
Political considerations will also be in the back of the justices' minds, the experts said. The challenge to the Affordable Care Act is taking place in a presidential election year, and could strongly affect President Obama's re-election chances.
"If the court strikes down the act," Magarian said, "all of a sudden, the left/center-left is going to be whipped into a frenzy. The path of least resistance would be to uphold the thing and let the status quo stand."
But, some of the experts believe there's also a good chance the Supreme Court will punt on the issue, declaring that the time isn't right for judicial review of the Affordable Care Act.
"I think it's interesting they're going to spend a lot of time -- a third of oral arguments -- on whether the case is 'ripe' for judicial review," said Drexel's Field. "That could be a signal from the court that they're spending that much time on that part of the argument."
Added Allison Orr Larsen, an assistant professor of law at the College of William & Mary in Williamsburg, Va.: "My best guess would be they don't decide it on the merits."
The reason why: the individual mandate, which takes effect in 2014, is a form of tax, and federal law doesn't allow a legal challenge to a tax that has yet to be collected.
"You can't challenge a tax until after you've paid it, and then you can sue for a refund," Larsen said, noting that this legal argument has come up in some lower court rulings on the law.
Such a ruling would delay any challenge to the Affordable Care Act until 2015. This would give the Supreme Court the chance to take the issue off the table in an election year while not explicitly endorsing or scuttling the law. "That's why I think it would be an attractive option for them," Larsen said.
Field agreed. "There's a good chance that they'll do that," he said. "The public might be left very frustrated, from not having a definitive answer, but we should be prepared for that outcome."
All the legal observers believe that the court's reasoning will become much clearer during the three days of arguments that begin on Monday.
"Because the hearing is going to be so long, I think we're going to come out of it with a good idea of what the justices are thinking about," Magarian said.
For more about the current justices, visit the website of the Supreme Court of the United States.
To read an overview story on the Affordable Care Act, click here.
To learn more about the expansion of Medicaid under the Affordable Care Act, click here.
To learn more about the importance of the individual mandate to the Affordable Care Act, click here.