Progressive candidates appear to have an edge in Colorado’s Democratic primaries next week. DENVER — The insurgency rocking the Democratic Party is set to reach mile-high heights on Tuesday, with a trio of primaries in Colorado giving voters a chance to express their anger with the party’s establishment. The Colorado races are distinct: an ideological battle for a safe blue House seat in Denver, a governor’s race where a longtime senator is in an unexpectedly tight race and a fight for the