It turns out last weekend’s violent white-power protest in Virginia was spurred in part by an ex-con and one-time Silicon Valley resident who’s about to bring his bare-knuckled activism back to the Bay Area. Nathan Damigo is not a techie. But the former Marine infantryman and convicted armed robber who founded the Oakdale-based white-nationalist group Identity Evropa grew up and went to school in San Jose before following a path into alt-right power politics. Damigo, who made the news after he was arrested for punching a woman in the face during the so-called “Battle for Berkeley” on April 15, now...