A Washington mega-lobbyist turned master political strategist, Mississippi Governor Haley Barbour is universally revered among influential Republicans. But cachet in the smoke-filled backrooms of D.C. and a turn as the popular executive of a conservative Southern state does not a successful presidential candidate make. After early flirtations produced little traction in the polls and a string of national reporters scrutinized his controversial statements on the civil rights era, Barbour decided in April that he would prefer a more familiar role in 2012 — playing gatekeeper to the highest echelons of the moneyed GOP establishment.