M. Caldwell Butler, who as a first-term Republican representative from Virginia wept after he voted to impeach President Richard M. Nixon, whose landslide 1972 re-election victory had propelled Mr. Butler into Congress, died on Tuesday in Roanoke, Va. He was 89.M. Caldwell Butler, former Republican congressman from Roanoke, dies at 89Washington Post / July 29http://www.washingtonpost.com/politics/m-caldwell-butler-former-republican-congressman-from-roanoke-dies-at-89/2014/07/29/174f2d7e-1741-11e4-9e3b-7f2f110c6265_story.htmlCaldwell Butler dies, recalled as being "free of politics'Roa...