Nearly two months after dropping his bid for the GOP nomination, Herman Cain’s presidential campaign paid about $19,000 to a pair of nonprofit groups that are reportedly under federal investigation for boosting his White House bid. The Wisconsin-based groups, Prosperity USA and Wisconsin Prosperity Network, were run by Cain’s top aides and footed the bill for about $40,000 of goods and services — including iPads and chartered flights — that helped Cain’s campaign get going early last year, according to documents obtained by the Milwaukee Journal Sentinel. The Wisconsin-based groups, Prosperity USA and Wisconsin Prosperity Network, were run by Cain’s...