It’s not unusual for candidates to use leftover cash from aborted campaigns to form political action committees. But traditionally politicians have opted for so-called leadership PACs that allow them pay for political staff, travel the country and dole out contributions to favored candidates – all of which helps them keep themselves in the political spotlight and curry favor for potential future runs. Super PACs, which were spawned by a 2010 federal court ruling, could be used to maintain a political staff and fund a politician’s travel, but not to make donations to candidates. On the other hand – unlike leadership...