Barack Obama's healthcare reforms, passed almost exactly two years ago, remain one of the most contentious aspects of his presidency. The bill was passed in the teeth of vociferous opposition from the Republican Party. Polls suggest that public opinion remains sharply divided. A key provision that individual citizens should either buy health insurance or pay a penalty, the so-called individual mandate, has already been the subject of numerous legal challenges across the country. It was almost inevitable that the issue would ultimately reach the highest court in the land. The nine justices who make up the Supreme Court, five of them regarded as conservatives, will spend a highly unusual three days hearing oral arguments. They'll issue their findings in the summer, just as this year's presidential election campaign swings into full gear. The impact on the campaign of a ruling on such an important political issue could be enormous.