NEW : Justices Samuel Alito , Clarence Thomas dissent . NEW : Justice Antonin Scalia joins the majority opinion in a case that could have major implications for campaign finance law and other areas of government regulation. Writing for the majority , Justice Ruth Bader Ginsburg took a practical approach , saying it is important to preserve judicial discretion , while ensuring most sentences remain within federal guidelines established two decades ago to ensure a measure of uniformity . Ruling aims to shrink disparity between powder cocaine and crack sentences .
NEW : Justices Samuel Alito , Clarence Thomas dissent . NEW : Justice Antonin Scalia joins the majority opinion in a case that could have major implications for campaign finance law and other areas of government regulation. Ruling aims to shrink disparity between powder cocaine and crack sentences .