At least one reason was the widespread infiltration of those types of groups. The FBI, rightly so, cracked down hard. A whole bunch of people, including my old ex-police officer boss, stepped forward to work their way into and inform on those groups. My boss was moved to a rural police department, spent two years gaining their trust, and then helped the FBI raid and dismantle a militia group.

There was a lot of good work that people did to counter that threat.