DENVER — Democratic socialists struck another blow against the Democratic establishment on Tuesday in Colorado, where 29-year-old Melat Kiros is projected to win against incumbent Rep. Diana DeGette, who was first elected before Kiros was born, in a primary.Kiros was the third progressive challenger to defeat a sitting House member in eight days, after two more won last week in New York.And, after successes in mayor’s races, congressional primaries and more on both coasts, Kiros’ win showed the expanding geographical reach of the left-wing insurgency seeking to remake the Democratic Party ahead of this year’s midterm elections — and as the 2028 presidential primary looms increasingly large.“We are winning from coast to coast, from every level of office. We are taking back our party and our country,” Kiros told supporters at her election night party.The 1st District primary was the most surprising outcome on a day in which Colorado Democratic voters settled a series of battles over who will lead the party as term-limited Gov. Jared Polis departs.Those voters opted to keep their two Democratic senators in the Senate. That was good news for Sen. John Hickenlooper, who fended off a challenge from the left. But it was bad news for Sen. Michael Bennet, who lost the party’s primary for governor to state attorney general Phil Weiser.Weiser campaigned on confronting President Donald Trump more aggressively than Polis, who was recently rebuked by his own party for deciding to grant clemency to election denier Tina Peters.Democratic voters also chose their nominee in the battleground 8th District race, projected to pick a 31-year-old state lawmaker to take on a freshman Republican in what’s expected to be one of the nation’s most competitive races in the battle for House control.