The Supreme Court Could ???Blow A Big Hole??? In Obama???s Legacy This Year ???The highest court in the land has now spoken,??? an elated and relieved President Obama said after the Supreme Court upheld a key provision of the Affordable Care Act in 2012. Now the law -- a centerpiece of Obama???s presidency -- is before the Court again after the justices announced last Friday that they would hear a fresh challenge to an important part of Obamacare. ???Health Care is the most important part of the president???s legacy, and the most unstable part of his legacy,??? said Julian E. Zelizer, a professor of history and public affairs at Princeton University. ???Clearly the Court can have an impact on one of the pillars of his presidency in a negative fashion.??? To be sure, the 2012 case was different. It was a constitutional challenge to the individual mandate that required most Americans to buy health insurance or pay a penalty. The Court upheld the Affordable Care Act when Chief Justice John Roberts stunned conservatives by casting his vote with the liberals. ???Had the conservative justices picked up the vote of Chief Justice John Roberts they would have thrown out the entire Affordable Care Act including the Medicaid expansion and the Medicare reforms,??? said Timothy S. Jost, an expert on health law at Washington and Lee School of Law. The new challenge has to do with a different part of the law concerning subsidies granted to low and moderate income Americans who seek to obtain affordable insurance from market places called ???exchanges.??? Millions of Americans take advantage of the subsidies. Sixteen states have established exchanges of their own while about 34 states rely on exchanges run by the federal government. . Challengers say the language of the law makes clear that only those living in the states with state-run exchanges can receive the tax credits. That would disqualify millions of individuals who rely on the federally-created exchanges. Democrats involved in drafting the law say such an interpretation thwarts Congress??? fundamental purpose of making insurance affordable to all Americans. ???While a victory for the challengers here would not destroy the whole law,??? Jost said, ???it would blow a big hole in it.??? A judgment for the challengers would lead to widespread destabilization of the individual insurance market, he added: ???Insurance will simply be far less accessible in two thirds of the states to anyone who does not have insurance through their employer or a government program??? In the next few weeks briefs will start rolling into the Court and legal observers will study Chief Justice John Roberts, who likely holds a big chunk of the president???s legacy in his hands.