The media's rules didn't apply to George W. Bush
The Atlantic's Marc Ambinder writes  about the consequences for politicians who exaggerate their military record:
In the United States, military service is sacral; it conveys an instant authority, a pedigree, a cultural backstop for character. Lying about it, even exaggerating about it, is therefore instantly disqualifying.
But that isn't always the case. It wasn't disqualifying, instantly or otherwise, for George W. Bush. During his 2000 and 2004 campaigns, the press didn't much care about Bush's exaggerations and lies about his military record. And I don't just mean the fact that all available evidence suggests that Bush failed to fulfill his commitment to the National Guard. Even if, for some reason, you choose to believe -- absent any evidence -- that Bush did fulfill that commitment, he exaggerated or lied about his service in other  ways , like claiming to have served in the "Air Force" and claiming to have continued flying with his unit for "several years" after his pilot training.
Not only did the media not treat Bush's exaggerations as disqualifying, in many cases, they harshly attacked  Democrats for raising questions about Bush's service.