Two conservative federal judges have now voiced cautiously sympathetic views on legal challenges to the 2,400-page health-care law that President Obama signed into law in March. But such preliminary skirmishes shed little light on whether the Supreme Court will in the end strike down the law, a law that raises a completely novel legal issue: can Congress require millions of individuals to buy a commercial product (in this case health insurance) in the name of regulating interstate commerce.

Judge Roger Vinson of the federal district court in Pensacola, Fla., suggested during a two-hour hearing on Sept. 14 that he was unlikely to dismiss a major challenge to the law by officials of 20 states, almost all of them Republican, plus three other plaintiffs. The plaintiffs object to provisions including the new law’s "individual mandate," an unprecedented requirement that people not covered by employer-based plans must buy comprehensive health insurance or face monetary penalties. It is to take effect in 2014.

The lawsuits-more than 15 so far-argue that Congress has no such power. Last month, federal district Judge Henry Hudson, of Richmond, Va., rejected a Justice Department motion to dismiss a similar suit by Virginia’s attorney general. But some leading legal experts, especially defenders of the new law, confidently predict that if any federal appeals court strikes it down, the Supreme Court will step in to uphold it, with some predicting a margin as lopsided as 8 to 1.