Justice Ginsburg drafted healthcare dissent before seeing Roberts's opinion

Supreme Court Justice Ruth Bader Ginsburg said she was writing a dissent in the court's healthcare case before she had seen a copy of Chief Justice John Roberts's majority opinion.

Ginsburg discussed the healthcare case in an interview with Reuters. She said it was clear immediately following oral arguments in March that the Obama administration was going to lose its main argument — that the healthcare law's individual mandate was constitutional as a regulation of interstate commerce.

Roberts and the court's four other Republican appointees appeared hostile to the Commerce Clause defense during oral arguments. Roberts's decision, while upholding the healthcare law, sided with the law's challengers on the Commerce Clause.

Ginsburg wrote a dissent on the Commerce Clause front. She told Reuters she started on the Commerce Clause dissent before she had seen Roberts's decision upholding the mandate under Congress' power to levy taxes.

"I had a draft of the dissent before the chief circulated his opinion because I knew it would be impossible to do" amid the crush of work at the end of the court's term, Ginsburg said in the Reuters interview.

Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas and Samuel Alito also wrote a dissenting opinion in the healthcare case, which sharply criticized the majority ruling upholding the health law.

The way the conservatives' dissent referred to Ginsburg's opinion sparked the first speculation that Roberts might have changed his vote in the healthcare case — which CBS News later confirmed, citing sources inside the court.

Ginsburg preemptively refused to comment on Roberts's decision-making during the Reuters interview, though she said there's nothing wrong with a justice changing his or her mind.

"People change their minds about what they thought," she said. "So it isn't at all something extraordinary, and that's how it should work. We're in the process of trying to persuade each other and then the public."

Scalia has also said in interviews this summer that he has changed his mind in some cases. He has downplayed reports of personal animosity among the justices stemming from Roberts's switch and the subsequent leaks to CBS.