The Justice Department stepped in to an ongoing Arizona election lawsuit Monday, supporting a claim by the League of Women Voters of Arizona that monitoring ballot drop boxes can amount to illegal voter intimidation. The department said such “vigilante ballot security measures,” including filming voters at drop boxes, probably violates the federal Voting Rights Act. “When private citizens form ‘ballot security forces’ and attempt to take over the State’s legitimate role of overseeing and policing elections, the risk of voter intimidation — and violating federal law — is significant,” the department said in a “statement of interest” filed in the...