The US Supreme Court opens a new session today with an unexpected challenge. President Obama's healthcare reform requires all Americans to buy health insurance, but 26 states have sued, claiming that's unconstitutional. The federal courts are so divided that the Obama Justice Department has now asked the Supreme Court to resolve the issue once and for all. That could be a major gamble for his re-election campaign, depending on whether the court takes the case, what it decides and when. With health costs and premiums rising, it also poses a lingering question: should the President have proposed a single-payer plan in the first place?