Mitt Romney's latest ad uses the sometimes-nasty Democratic primary from 2008 to cast President Obama as a serial negative campaigner. From Politico: 

The ad pulls footage of the 2008 primary campaign, when Clinton -- at a campaign stop in Ohio, then-Gov. Ted Strickland at her side -- denounced the Obama team for "perpetuating falsehoods."

Buzzfeed reports the ad is running in Iowa, Virginia, North Carolina, Colorado, New Hampshire, and Nevada as well as Ohio.