Eric Cantor sat in his Washington office in June after one of the biggest upsets in congressional history, getting encouragement from JPMorgan Chase & Co.’s Jamie Dimon, head of the largest U.S. Dimon talked about being fired from another bank by his mentor before rebounding to an even better seat, according to two people who were there. Cantor, 51, started this month as a managing director and vice chairman of New York-based investment bank Moelis & Co. (MC), where he’ll earn more than $3.4 million by the end of next year.