Mr. McMillan declined to show the apartment, saying he feared for his neighbors’ safety, and fielded questions from the driver’s seat of his parked graphite-colored Honda CR-V, which is also his mobile office. When he travels, he sleeps in it, too; in the back were a sleeping bag, a bottle of Scope Original Mint mouthwash and a pair of nunchucks he keeps in a seat-back pocket. That weapon happens to be banned by the state he wants to run. “My main object is to protect myself,” he said. “I will worry about the consequences later on.”