Reaching for seemingly any reasonable explanation for Obama's stunning listlessness at yesterday's presidential debate, former Vice President Al Gore offered up a "controversial" suggestion: It's the altitude, stupid.

"I'm going to say something controversial here," Gore told Current TV host Cenk Uygur. "Obama arrived in Denver at 2 p.m. today, just a few hours before the debate started. Romney did his debate prep in Denver. When you go to 5,000 feet, and you only have a few hours to adjust... I don't know."

Even Uygur wasn't buying it, countering that he too had just flown in to Denver from LA, and took care of his doldrums with "two cups of coffee."

[video via MSN Now]