The U.S. Supreme Court largely upholds President Barack Obama’s Affordable Care Act in a 5-4 decision. A lawsuit had challenged a key provision – the individual mandate that required all Americans to buy insurance or pay a fine – as unconstitutional under the commerce clause. But the opinion, written by Chief Justice John G. Roberts Jr., says that the fine is a tax, which the government has the authority to impose. The ruling does restrict the law’s expansion of Medicaid. States are given some flexibility not to expand their programs without facing financial penalties outlined in the law.