The U.S. Supreme Court has agreed to decide whether Congress overstepped its powers when it approved President Obama’s healthcare law last year. The court is expected to issue a ruling by July — just months before the 2012 presidential election. Over two dozen states have asked that the entire law be struck down. At the heart of the legal battle is the section of the law that requires all Americans to buy health insurance by 2014 or pay a penalty, a provision known as the individual mandate.