washington u.s. supreme court monday turn away republican challenge federal campaign finance restriction prevent political party raise unlimited amount cash spend support candidates republican party louisiana argue provision 2002 bipartisan campaign reform act violate free speech right u.s. constitution justices let stand low court rule reject republican challenge brief order note conservative justices clarence thomas neil gorsuch favor hear case conservative-leaning court recent years roll back campaign finance restrictions 2010 court pave way unlimited outside spend elections case call fec v. citizens unite concern corporate spend 2014 court strike limit total amount individuals donate federal two-year election cycle decisions erode section 2002 law measure commonly know mccain-feingold law two senators sponsor republican john mccain democrat russ feingold bar state local party take unlimited donations activities concern federal elections donations often call soft money unregulated key target 2002 law supreme court previously turn similar case challenge party campaign finance restrictions include one 2010 citizens unite decision focus national party bring republican national committee u.s. supreme court leave key campaign finance restriction place