SILVERTON, Colo. — It’s hard to say precisely when Silverton, Colorado, started to come apart, but the town election of April 7, 2020, might be a good moment to begin the story. That was when a young, progressive New York lawyer and adventure skier named Shane Fuhrman beat the longtime fire chief Gilbert Archuleta, part of Silverton’s old guard, by 10 votes to become the new mayor. To supporters, mainly of his generation, Fuhrman, 42, represented progress. After working at top finance firms in M