The first issue, in three days of scheduled arguments, was whether the high court could handle a challenge to the Patient Protection and Affordability Care Act now or have to wait until its provisions are fully implemented, which won't happen until 2014.
The question was whether the 19th century Anti-Injunction Act precludes court action now.
SCOTUSBlog reported questioning by justices indicated they do not believe the more than century-old law precludes action now, with Justice Antonin Scalia suggesting any restraint on the court should be interpreted narrowly and Justice Samuel Alito indicating he does not think the Anti-Injunction Act is applicable.
Justices Stephen Breyer and Sonia Sotomayor asked questions indicating they may not consider as taxes the law's individual mandate and penalties for not buying health insurance.
The main provision of the Affordable Care Act being challenged -- the requirement that everyone who can afford it obtain insurance or else pay a fine -- does not go into effect until 2014. If the act bans the current court case, it would be 2015 before the constitutionality of the individual mandate could be thrashed out in the courts.
Ilya Shapiro, senior fellow in constitutional studies at the Cato Institute and editor-in-chief of the Cato Supreme Court Review, described Monday's argument as "the calm before the storm."
"There were also hints that the court was skeptical of the government's backup merits argument that the individual mandate was justified under the Constitution's taxing power," he said. "Perhaps the only surprising aspect of today's hearing was how 'cold' the bench was; it's rare for the justices to allow advocates to speak at length without interruption, but that's what they generally did today. That's yet another indication that the court will get past the [Anti-Injunction Act] appetizer to the constitutional entree."
Arguments continue Tuesday when the justices hear a 2-hour debate regarding the individual mandate.
The thrust of the argument is whether the individual mandate exceeds congressional power outlined in Article I of the Constitution.
The requirement that most individuals get health insurance "is a valid exercise of Congress' commerce power," the administration said in a brief to the high court.
On Day 3 of the arguments, Wednesday, the justices will hear a 90-minute debate on whether the individual mandate can be "severed" from the rest of the law. In other words, if they strike down the mandate, does the rest of the law go down with it?
Also Wednesday, the justices hear 60 minutes of argument on the healthcare law's expansion of Medicaid, the joint federal-state program that provides healthcare for the poor.
In a brief, the 26 states challenging the law said the states want to know if Congress exceeds "its enumerated powers [in the Constitution] and violates basic principles of federalism when it coerces states into accepting onerous conditions that it could not impose directly by threatening to withhold all federal funding under the single largest grant-in-aid program [Medicaid]?"
Any threat of a Medicaid cutoff is serious. Medicaid -- for which states provide about half the funding -- accounts for more than 40 percent of all federal funds dispersed to states -- $251 billion in 2009 alone -- and approximately 7 percent of all federal spending.