EDMUND GIBSON ROSS
He cast the deciding vote to acquit in the Andrew Johnson impeachment. He was the last of only 7 Republicans voting to acquit. His vote meant there would not be the required two/thirds of the Senate to vote in order to remove Johnson from office. His constituents were so angry with him that he was never reelected.
Edmund Gibson Ross was a politician who represented Kansas after the American Civil War and was later governor of the New Mexico Territory. His vote against convicting President Andrew Johnson of "high crimes and misdemeanors" allowed Johnson to stay in office by the margin of one vote. As the seventh of seven Republican U.S. Senators to break with his party, he proved to be the person whose decision would result in conviction or acquittal. When he chose the latter, the vote of 35–19 in favor of Johnson's conviction failed to reach the required two-thirds vote. Ross lost his bid for re-election two years later.