Last year's financial meltdown rightfully destroyed former Federal Reserve Board Chairman Alan Greenspan's reputation as an infallible "wise man," but he said something wise in his 2007 memoirs, describing a constitutional amendment he'd been "pushing for years."

Wrote Greenspan: "Anyone willing to do what is required to become president of the United States is thereby barred from taking that office. I'm only half joking."

It's no laughing matter. After all, what sort of person wants the job badly enough to spend years living out of a suitcase, begging for cash, glad-handing through primary states, and saying things that no intelligent person could possibly believe?

Greenspan's point was that people who seek the presidency today display a pathological power lust that...