Americans for Prosperity, the Tea Party organization backed by the Koch brothers, is set to begin a $25 million advertising assault aimed at President Obama, its largest effort to date.

The super PAC said the first of several ads would begin Wednesday in 11 states, including Minnesota, Wisconsin and Iowa. The campaign will run through Labor Day weekend.

The first ad, titled "President Obama: A One-Term Proposition," blasts Obama over the rising national debt. The commercial focuses on an excerpt from an interview Obama gave to NBC News at the beginning of his term in which he pledged to cut the debt. It was during that interview that he uttered the phrase that his rivals now regularly use against him: "I will be held accountable."