The survival of President Barack Obama's health care overhaul rests with a Supreme Court seemingly split over ideology and, more particularly, in the hands of two Republican-appointed justices.

Chief Justice John Roberts and Justice Anthony Kennedy put tough questions to administration lawyers defending the health care law during three days of arguments that suggested they have strong reservations about the individual insurance requirement at the heart of the overhaul and, indeed, whether the rest of the massive law can survive if that linchpin fails.
 
But Roberts and Kennedy also asked enough pointed questions of the law's challengers to give the overhaul's supporters some hope. In any event, justices' questions at arguments do not always foretell their positions.

The court's decision, due in June, will affect the way virtually every American receives and pays for health care and surely will reverberate in this year's campaigns for president and Congress. The political effects could be even larger if the court votes 5-4 with all its Republican-appointed justices prevailing over all the Democratic appointees to strike down the entire law, or several important parts of it.

Not since 2000, when the court resolved the Bush v. Gore dispute over Florida election returns that sealed George W. Bush's election as president, has a Supreme Court case drawn so much attention.

The court wrapped up public arguments Wednesday on the overhaul, which aims to extend health insurance to most of the 50 million Americans now without it. The first and biggest issue the justices must decide is whether the centerpiece of the law, the requirement that nearly all Americans carry insurance or pay a penalty, is constitutional.