Perhaps the best evidence of this is a perpetual donation to the William J. Clinton Foundation from Canadian tycoon Frank Giustra, in which Giustra has promised to give the charity half of the future profits from his global mining empire for the rest of his life.

The unorthodox arrangement could present ethical concerns for Sen. Clinton if foreign governments believe they can curry favor with her by helping Giustra's far-flung mining operations, or if they fear that restricting his activities would damage their relations with her.

"It presents a really serious problem because the decisions a Secretary Clinton might make could be perceived as affecting the [charity's] cash flow," said Stephen Gillers, a legal ethics expert at New York University School of Law.

This would be a problem if left untouched. But it has a couple of fairly easy solutions. Giustra can either now re-pledge a flat sum based on a very conservative estimate of his future profits. Or he can simply volunteer to give it to some other AIDS-fighting do-gooder group, perhaps the One Campaign. If saving lives and not zooming around private jets is what Bill really cares about then he ought to be fine with this.

--Michael Crowley