Bill Clinton's memoir will hit bookstores later this month, but one story you're not likely to read in its pages involves Clinton's friendship with Arthur A. Coia. The debonair former president of the Laborers International Union of North America (LIUNA) was one of the Democratic Party's biggest contributors when Clinton was in office. In the first four years of the Clinton administration alone, LIUNA gave $4.8 million to Democrat candidates and the Democratic Party. Although Clinton had contact with Coia no fewer than 120 times, their association is an awkward memory for the former president given the latter's ties to...