The McCain campaign has fallen upon a mocking metaphor for Obama's energy policy:

On the trail today, McCain chided his opponent by saying "We're not going to achieve energy independence by inflating our tires."

The McCain campaign, and the GOP in general, indeed has an opening on energy with voters. But it seems that there is a trend developing in the McCain camp to go for the quick joke when it might be better served in the long run by being a bit more serious.

After all, McCain is the experienced statesman, who wants Americans to believe his opponent is a naive wunderkind. Constantly going for the quick gag could begin to wear thin after a while.