When the Supreme Court takes up yet another challenge to the president's health care law in March, the outcome could have a devastating impact on millions of Americans receiving subsidized health coverage through its exchanges. Almost immediately after the court announced it would hear King v. Burwell, the now-famous case that centers on whether people enrolled on the federal exchange can receive federal subsidies, legal experts began predicting grave news for Obamacare. In King v. Burwell, the plaintiff challenges language in the law that says enrollees can receive insurance subsidies when they purchase health insurance on an exchange "established by the state."