Will the people rule? . . . Is democracy possible?  —Lincoln Steffens

In the early 1990s, when he was running for office and losing just about every year, John O’Hara was known as “Mad Dog” for his quixotic campaigns. Appropriately, his political enemies wanted the young lawyer “leashed, muzzled, and caged, if not shot,” as one of them put it to me. Such was the notoriously vindictive — some would say corrupt — atmosphere of Democratic machine politics in Brooklyn. In the old days, insurgents got their legs broken by plug-uglies, or lost ferociously at the polls by the…