A federal judge on Wednesday dismissed riot charges against two members of a neo-Nazi street gang who had attacked counterprotesters at several pro-Trump rallies in California in 2017, saying that the government had behaved improperly by neglecting to bring charges against left-wing activists who had also acted violently at the same events. The ruling by the judge, Cormac J. Carney, found that prosecutors had unfairly engaged in “a selective prosecution” against the two men — members of the Rise Above Movement, or R.A.M. — and targeted them chiefly because of their vitriolic speech and white supremacist ideology. While Judge Carney...