WASHINGTON — U.S. Rep. Kelly Armstrong won North Dakota's race for governor on Tuesday. The third-term Republican congressman and attorney bested Democratic state Sen. Merrill Piepkorn to succeed two-term Gov. Doug Burgum, who didn't seek a third term. Armstrong continues Republicans' dominance in North Dakota, where the party has held the governor's office since 1992 and a Democrat has not won a statewide race since 2012. Armstrong also is a former state senator and state party chair. The Associated Press declared Armstrong the winner at 9:00 p.m. EST.