Last night to David Letterman, John McCain explained his earlier cancellation to his Late Show by saying “I screwed up.”

Funny? Maybe.

Pertinent? No way.

In the largest and most serious crisis in decades, McCain made the right decision to suspend his campaign three weeks ago, but his explanation for doing so has been woefully anemic. And though he could have done it with some levity suitable for Letterman’s environment, he should have explained himself to the largest Late Show audience in years.

Instead, he punted.

He also poked fun at himself at the Smith dinner Thursday night over the same issue of suspending his campaign. Again, it was a time to be funny but perhaps he should have focused on a different topic.

Everything indicates that this decision to suspend, its subsequent inept explanation and failure to pin this banking debacle on its proper Democrat culprit was the turning point in this election.

One might wonder if McCain has already conceded and is looking for a way to comfortably slide back into his old role as maverick senator with friends on the left and right.