Remember Rosie Ruiz? In 1980 she was the first woman to cross the finish line at the Boston Marathon — except it turned out that she hadn’t actually run most of the race, that she sneaked onto the course around a mile from the end. Ever since, she has symbolized a particular kind of fraud, in which people claim credit for achieving things they have not, in fact, achieved.

And these days Paul Ryan is the Rosie Ruiz of American politics.

This would have been an apt comparison even before the curious story of Mr. Ryan’s own marathon came to light. Still, that’s quite a story, so let’s talk about it first.

It started when Hugh Hewitt, a right-wing talk-radio host, interviewed Mr. Ryan. In that interview, the vice-presidential candidate boasted about his fitness, declaring that he had once run a marathon in less than three hours.

This claim piqued the interest of Runner’s World magazine, which noted that marathon times are recorded — and that it was unable to find any evidence of Mr. Ryan’s accomplishment. It eventually transpired that Mr. Ryan had indeed once run a marathon, but that his time was actually more than four hours.