By REBECCA BOONE, GILLIAN FLACCUS and MICHAEL KUNZELMAN BOISE, Idaho (AP) — As rioters laid siege to the U.S. Capitol, the seat of American democracy became a melting pot of extremist groups: militia members, white supremacists, paramilitary organizations, anti-maskers and fanatical supporters of President Donald Trump, standing shoulder to shoulder in rage. Experts say it was the culmination of years