“My chance of surviving prostate cancer — and thank God I was cured of it — in the United States? Eighty-two percent,” says Rudy Giuliani in a new radio ad attacking Democratic plans for universal health care. “My chances of surviving prostate cancer in England? Only 44 percent, under socialized medicine.”

It would be a stunning comparison if it were true. But it isn’t. And thereby hangs a tale — one of scare tactics, of the character of a man who would be president and, I’m sorry to say, about what’s wrong with political news coverage.

Let’s start with the facts: Mr. Giuliani’s claim is wrong on multiple levels — bogus numbers wrapped in an invalid comparison embedded in a smear.

Mr. Giuliani got his numbers from a recent article in City Journal, a publication of the conservative Manhattan Institute. The author gave no source for his numbers on five-year survival rates — the probability that someone diagnosed with prostate cancer would still be alive five years after the diagnosis. And they’re just wrong.