Undeterred by independent fact-checkers that have debunked the thrust of their claims, the Obama campaign is redoubling attacks on Mitt Romney as an "outsourcer" in a new TV ad airing in eight battleground states.

The 30-second spot — titled "The Problem" — claims Romney condoned the Chinese "taking our jobs and taking a lot of our future."

We found no evidence to support the claim that Romney — while he was still running Bain Capital — shipped American jobs overseas," FactCheck.org concluded in a report last month

Washington Post fact checker Glenn Kessler also concluded that while Bain-owned companies may have engaged in outsourcing, Romney's ties to the practice are tenuous.