John Roberts could again make or break Obamacare

WASHINGTON - Speaking in September to law students in Nebraska, Chief Justice John Roberts said the U.S. Supreme Court needs to avoid the partisan rancor that has enveloped the other two branches of government.

"I don't want it to spill over and affect us," he said. "That's not the way we do business. We're not Democrats or Republicans in how we go about it."

Now, for the second time since 2012, the nation's highest court will decide the fate of one of the most divisive issues in U.S. politics: the Affordable Care Act (ACA). And Roberts, the Republican appointee who cast the vote that saved the health care law two and a half years ago, is the focus of most of the attention.

That's because he joined four Democratic-appointed justices to reject the earlier challenge to the health care law, dismaying conservatives amid a report that he switched sides late in the deliberations. The question is whether he'll back the law again.

"All the court-watcher chatter has been about the chief," said Kevin Walsh, a constitutional law professor at the University of Richmond (Va.) School of Law.

Supporters of the law, President Obama's most important domestic initiative, are particularly concerned, because many never expected the high court to take up the case, which centers on subsidies created under the measure. Arguments probably will be in early March.

Some say the court's decision to hear the dispute was politically driven. The justices accepted the case in the absence of the type of lower-court disagreement that traditionally triggers Supreme Court involvement. And the case centers on what in other contexts would be a routine question of statutory interpretation — four words in the 900-page law — not a pathbreaking constitutional issue.

Stoking those fears is the difficulty in reading Roberts, 59, who was selected by President George W. Bush in 2005.

Roberts has often expressed concern for the court's institutional legitimacy, which might counsel against overturning a major piece of legislation on party-based lines. At the same time, a ruling against the administration would let him reclaim the favor of legal conservatives.

John Yoo, a professor at the University of California's law school in Berkeley, wrote that the new case gives Roberts "the chance to atone for his error" in 2012.

The case will test Roberts' description of his job as that of an umpire calling balls and strikes.

At issue is a provision in the 2010 health law that gives tax credits to people when they buy insurance on an online exchange "established by the state."

The showdown comes at a precarious time for the ACA. A recent Gallup poll indicates the law has never been less popular, with 56 percent of Americans saying they disapprove of the statute compared with just 37 percent who like it.

In the last challenge to the law, in 2012, Roberts kept the court from dividing along party lines, when he voted to uphold the requirement that people buy insurance or pay a penalty. The other four Republican appointees said the provision violated the Constitution, and they would have invalidated the entire law.