A key attorney general challenging the Affordable Care Act at the Supreme Court walked out of the building this morning predicting that the justices would rule the health care law unconstitutional.

Pam Bondi, the Republican AG of Florida, told reporters on the steps in front of the Supreme Court that all nine justices "expressed concern" about the so-called mandate in the law that requires Americans to buy health insurance or pay a fee.

ObamaCare supporters say the fee is merely a tax, while its critics say the mandate unfairly makes people do something they otherwise might not want to.

"They do not believe this is a tax," Bondi said of the justices.

The mandate will be debated more tomorrow.

"I felt very confident," Bondi said as she was surrounded by other attorneys general challenging the law.