Remember — assuming you're old enough to remember — how back in 1987, Senator Gary Hart of Colorado looked like a shoo-in to be the Democratic nominee for President in '88? Then he was accused of having an affair. In those more innocent of times, that was enough to disqualify him for the job even though there was no proof the charge was true.
In this article, James Fallows looks at the very real possibility that Hart was framed as part of a political dirty trick that did what it was supposed to do: Get him out of the race.