Audio: Justices hear arguments on Anti-Injunction Act

Monday’s session, which launched three days of oral arguments in the historic case, also highlighted a potential weakness in the Obama administration’s defense of the healthcare law’s mandate that people buy insurance.

The Justice Department says the mandate is constitutional, in part, under Congress’s power to levy taxes.

But in urging that the justices should not postpone a decision until the mandate takes effect, sometime after 2014, the administration has had to argue that the mandate is not a tax.

Justice Samuel Alito raised the issue as Solicitor General Donald Verrilli Jr. argued Monday that the fine is a not a tax.

“Tomorrow you’re going to be back, and you’re going to be arguing that the penalty is a tax,” Alito said.

Although that distinction could cause problems during Tuesday’s arguments on the constitutional merits of the mandate, the justices seemed inclined during Monday’s arguments to side with the Justice Department and issue a ruling now.

Read more on The Hill's Healthwatch Blog.