A dozen paid operatives registered with Arizona’s secretary of state on Sunday to collect signatures on behalf of left-wing presidential candidate Cornel West, listing their employer as a Republican-leaning firm that recently worked for GOP House candidate Blake Masters.

Arizona, unlike most states, requires paid or out-of-state petition-gatherers to register with the state. On their public registrations, some of circulators working to help West get on the ballot in Arizona struggled to…