Montana Gov. Steve Bullock announced Tuesday that he is seeking the Democratic presidential nomination, distinguishing himself among nearly two dozen candidates as the field’s only statewide elected official to win a state that President Donald Trump carried in 2016. The 53-year-old governor is running as a centrist Democrat who has advanced party values while navigating a Republican legislature and a GOP-leaning electorate. Bullock made his candidacy official in a video that capped months of speculation fueled by his political activity in Iowa, which hosts the nation’s first presidential caucus next February. He plans to address supporters later Tuesday in the...