It was the altitude. Yeah, that's it.

As liberal pundits cringed Wednesday night over President Obama's debate performance, Al Gore leapt to his defense with a curious explanation.

If Obama seemed like he had his head in the clouds, the former VP reasoned, perhaps it was because he was having trouble adjusting to the Mile-High City.

"I'm going to say something controversial here," Gore said on Current TV, the channel he helped found. "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 ..."

Gore trailed off with a chuckle, but his fellow co-hosts chimed in with agreement.

"Exactly," one of them said off-screen.

Co-host Cenk Uygur noted how when he came from Los Angeles, "You know what I did? I drank two cups of coffee before coming out here."

Another guest added: "It's really different. The first time I ever did stand up in Denver I had the same exact effect. I flew in that day and when your lungs aren't acclimated to that kind of air, yeah it makes you drawn. It makes you off. The president had an off-night."

Other Obama supporters weren't quite so willing to give the president a pass.

"I can't believe i'm saying this, but Obama looks like he DOES need a teleprompter," comedian and Obama supporter Bill Maher tweeted.