It's true. Five of the past six Presidential election cycles have featured showdowns between a veteran and a non-vet, and IN ALL FIVE ELECTIONS, the NON-VETERAN won.
In fact, going by the past 25 years of elections, those who did NOT serve in the military beat out those who did serve in the military.
In 1980, Ultimate Chickenhawk Ronald Reagan beat naval officer Jimmy Carter.
In 1984, Ultimate Chickenhawk Ronald Reagan demolished soldier Walter Mondale.
In 1988, WW2 vet George Bush beat Korea vet Michael Dukakis. That's the wash, as they're both veterans.
In 1992, "Draft-dodging" Bill Clinton beat WW2 vet George Bush.
In 1996, "Draft-dodging" Bill Clinton beat WW2 war hero Bob Dole.
In 2000, "AWOL-in-Chief" George W. Bush beat Vietnam vet Al Gore.
Judging by recent electoral history then, we risk going down soundly to defeat if we nominate any candidate with a military service record... goodbye Kerry, sayonara Clark.
This goes to show how false the memes can be. The idea that any candidate is "less electable" because of a lack of military service is simply a fallacy - and conversely, is evidence that a military service record is of no value in determining a candidate's affirmative electability.