Their plan has been praised widely, though not unanimously, by both liberals and conservatives. And sources on Capitol Hill say, if enacted, they hope it would moot the health care reform lawsuits by providing states a way around the federal insurance mandate.
It's not clear whether it would defuse those suits, though.
"I don't think it does," says Timothy Jost, a law professor at Washington and Lee University who's been watching the lawsuits closely. "The basic claim of the state lawsuits is that the federal government doesn't have any authority to impose an individual mandate at all, and therefore allowing some states to opt out of the individual mandate doesn't solve that problem."
"The argument is that Congress has no power to do this whatsoever," Jost adds, noting that he disagrees with the plaintiffs' position.
CMS Administrator Don Berwick has reacted favorably to the proposal at a Senate Finance Committee hearing last week. And it certainly would provide the administration with rhetorical cover against the opponents of the mandate.
But very few states currently have the infrastructure in place to successfully opt out (two of the exceptions are Brown's Massachusetts and Wyden's Oregon). That would leave the vast majority of Americans vulnerable to the mandate, and, according to Jost, that's why this might not be the legal silver bullet it supporters hope it would be.
Thirty Republican Senators have signed on to an amicus brief in support of a Florida lawsuit challenging the constitutionality of the mandate. Brown is not one of the 30.