Only three of the 12 appellate judges who have reviewed the law have decided it is unconstitutional to require all Americans to have health insurance. Not a single appeals court judge has said the entire law must be tossed out, the position advocated by Florida and 25 other Republican states leading the legal assault.The Supreme Court is expected to announce as soon as Monday that it will hear the Florida case, the largest and broadest challenge to the Patient Protection and Affordable Care Act.The string of appellate victories may not predict how the Supreme Court will decide the case. But some legal observers believe the recent decisions lay out a road map for preserving the law that may appeal even to some of the Supreme Court's more conservative members."They show that smart, principled conservatives can decide this is within the broad reach of Congress' power, even if they might think it is bad policy," said Richard Garnett, a law professor at the University of Notre Dame who was a clerk to former Chief Justice William H. Rehnquist.When the states and the National Federation of Independent Business filed suit in March 2010, they questioned whether Congress, under the guise of regulating commerce, could place an unprecedented requirement on Americans to buy health insurance starting in 2014.The so-called individual mandate was designed to spread risk more broadly and control insurance premiums, enabling the federal government to prohibit insurers from denying coverage to patients with preexisting medical conditions, a key promise of the law. Without a mandate, some Americans might avoid buying insurance until they got sick, dramatically driving up premiums.The insurance requirement became the focus of the litigation and initially sparked a partisan split among trial judges. But more recent rulings from appellate courts around the country have significantly muddied the liberal-conservative divide.