Election Fraud, Voter ID and Gerrymandering

Red-State Republicans are enacting laws to require voters to identify themselves at the polls with picture-identification not everybody has access to. Democrats claim the GOP is trying to rig next year's elections by depriving minorities, old people and college students from exercising the right to vote. Republicans claim that voter fraud threatens the integrity of elections, while Democrats call that a myth. Does either side have persuasive evidence? Also, which party will benefit most from redrawing Congressional district boundaries?