Richard Cordray speaks softly and carries a big stack: lime-green index cards, pressed into his shirt pocket, near enough for any sudden onset of note-taking. A former director of the Consumer Financial Protection Bureau, he has been endorsed in his bid for Ohio governor by Senator Elizabeth Warren, who has told him he needs to learn how to brag more. “I am pretty good at getting back people’s money,” Mr. Cordray managed before an outdoor crowd of dozens here recently. Polite applause followed. He is trying. Dennis Kucinich speaks until someone interrupts him — and even this is often insufficient...