Roberts not willing to go as far as conservatives on health law

(CBS News) Chief Justice John Roberts was ready to strike down the heart of the Affordable Care Act, CBS News chief legal correspondent Jan Crawford reports, but he wasn't ready to go as far as the other conservatives on the Supreme Court.

"He wasn't prepared to go quite as far as the other conservatives to strike down the entire law," Crawford said on CBS This Morning.

Last week, Roberts wrote the Supreme Court's majority opinion to uphold the individual mandate, keeping President Obama's health care law alive, even though as Crawford reported on CBS' "Face the Nation" on Sunday, he initially sided with the four conservative justices.

Why exactly Roberts ultimately decided to ally with the liberal justices is unclear, Crawford reports. "The conservative justices, according to my sources, say they are unsatisfied with his explanation for why he did shift his views," she said.

The court is notoriously tight-lipped about its proceedings, and the story behind the court's decisions can take weeks, months or even years to come out.

In this case, Crawford said, "There are so many people inside that courtroom... who know about this unusual shift, and many of them are quite upset about it. Sometimes people are willing try to explain what happened."

Roberts switched views to uphold health care law
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