In her Friday interview with Charlie Gibson, Sarah Palin said that Alaska "produces nearly 20 percent of the U.S. domestic supply of energy." McCain has said the same thing — in an interview with Univision that aired Friday, he said, "Alaska supplies 20 percent of America’s energy." It’s clearly an established campaign talking point.

Thing is, it’s false. FactCheck.org debunks it here. Alaska is responsible for 3.5 percent of domestic energy production, and 2.4 percent of the energy consumed in the U.S. Even if you conflate "energy" with "oil and gas" — as the campaign clearly intends — the claim doesn’t add up: The state produces 14 percent of U.S. oil and about 2 percent of U.S. natural gas.

To repeat: This assertion from the McCain/Palin campaign is demonstrably false, based on U.S. government sources. It’s been debunked several times. And yet they keep repeating it.

Why repeat lies? McCain spokesman Brian Rogers offered some insight in a quote to Politico: "We’re running a campaign to win. And we’re not too concerned about what the media filter tries to say about it."

Grist thanks its sponsors. Become one.

Will the aggressive, unapologetic lying work? There’s some evidence the dynamic is shifting. The Obama campaign released a blistering memo fact-checking a whole series of McCain campaign claims, which got picked up by several campaign reporters. The New York Times had a front-page story on Friday on McCain’s "distortions." The Washington Post, The Boston Globe, and Bloomberg have recently run harsh stories on the campaign’s knowingly-false statements (MSM still has trouble with the “lie” word). First Read says the wheels may be coming off the Straight Talk Express. And there’s this: