Democrat John Bel Edwards won election on Saturday as the next governor of Louisiana, staking a rare victory for his party in the conservative US South.Edwards, a 49-year-old state legislator, defeated Republican US Senator David Vitter in a hotly contested runoff election that defied the political headwinds in a state where Republicans currently hold all statewide offices. After his defeat, Vitter announced he would not seek another Senate term next year.With 99 percent of the precincts reporting, Edwards held a 56 percent to 44 percent lead.Edwards thanked his cheering supporters and said the election confounded conventional wisdom that he could not win."I will not let you down," he said. "This election shows us that the people of Louisiana in a time of deep cynicism about our politics and also our future, have chosen hope over scorn... and over a distrust of others."In a reference to Republican Gov. Bobby Jindal, who has been criticized for focusing on his presidential campaign at the expense of Louisiana, Edwards said the people of a state that is "embarrassed by the vanity and unrestrained ambitions of its leadership" have chosen to pursue a better future.