u.s. supreme court monday uphold federal disclosure rule political advertise reject appeal denver-based libertarian think tank want run ad without force divulge major donors denver-based independence institute sue federal election commission argue law require disclosure violate free speech right u.s. constitution first amendment supreme court affirm low court rule last year favor commission late decade-long series case bring conservatives aim roll back federal campaign finance restrictions independence institute support case influential republican conservative voice include republican senate majority leader mitch mcconnell judicial watch legal activist group well u.s. chamber commerce business group institute ahead 2014 congressional elections seek run radio advertisement increase prison cost tell listeners urge colorado u.s. senators support sentence reform ad mention senator name lead election trigger provision 2002 campaign finance statute know mccain-feingold law require institute file election commission disclose donors support ad law enact combat explosion know soft money campaign so-called sham issue advertisements cloak partisan advocacy discussions public policy though supreme court allow unlimited campaign spend corporations unions landmark 2010 decision citizens unite federal election commission case court also uphold disclosure requirements campaign ads federal election commission say century federal law require organizations influence elections disclose information fund source principle uphold citizens unite rule independence institute sue federal court washington bid keep name donors secret argue propose ad focus sentence reform senators consider senator re-election campaign last october three-judge panel federal court rule group say would impossible distinguish genuine issue ads reference candidates campaign-style ads openly promote disparage candidate u.s. top court reject challenge political ad disclosure rule