PHOENIX (AP) — A federal judge Friday refused to bar a group from monitoring outdoor ballot boxes in Arizona's largest county where watchers have shown up armed and in ballistic vests, saying to do so could violate the monitors' constitutional rights.

U.S. District Court Judge Michael Liburdi said the case remained open and that the Arizona Alliance for Retired Americans could try again to make its argument against a group calling itself Clean Elections USA. A second plantiff, Voto Latino, was removed from the case.

Liburdi concluded that "while this case certainly presents serious questions,...