Muckraker: Grist on PoliticsBarack Obama is hammering back after John McCain ran an ad comparing him to Britney Spears. In a new ad of his own, Obama accuses the Republican candidate of taking “the low road.”

“John McCain: Same old politics, same failed policies,” says the ad, before touting Obama’s plans to grant a $1,000 middle-class tax, fight Big Oil, develop alternative fuels, and “break the grip of foreign oil.” Watch it:

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