MADISON, Wis. -

In the last 28 days of the campaign, the candidates for U.S Senate are on the attack.

Sen. Ron Johnson uses Russ Feingold's past words against him in his latest ad.

"Feingold has a history of not telling the truth going back to 1992," the ad said.

Then they play two video clips of Feingold from that era.

"I will rely on Wisconsin citizens, not out-of-staters, to pay for this campaign," Feingold says in a campaign ad video. He follows that up by saying "I'm making a pledge for the future," in a separate interview from that year.

"70 percent of Feingold's money has come from out of state," the Johnson ad says.

News 3 finds this is true. Feingold made this pledge in a "Home Movies" campaign ad in 1992 in a contract to voters written on his garage. He re-iterated it in a C-Span interview.

"I'm saying that's a pledge I'm going to keep," Feingold told C-Span interviewers. "I'm not going to get in there and go 'Oh, where are the PACs, where are the out of state contributions.' I'm making a pledge for the future."

A look at numbers from the Center for Responsive Politics, which tracks elections spending, shows so far in 2016 that 69 percent of Feingold's contributions have come from out of state, compared to 46 percent for Johnson.

When we look at where the money came from, the majority comes from Madison, but New York City, Chicago and Boston round out the top five metro areas for donations. For Johnson, it's largely Wisconsin cities but Chicago is also included.

Feingold said this pledge went into the future, but he now says things have changed.

"What I said in 1992 whenever I said that I would get a majority of my contributions from Wisconsin citizens, I made that pledge for that term," Feingold said in a video clip from the ad. That's followed by a repeat of the clip saying "I'm making a pledge for the future."

News 3 finds this needs clarification.

Feingold did continue that pledge through other campaigns, numbers show in 2004 and 2010 that he did raise more in-state than out-of-state. But this year that figure has changed and Feingold further explained why in an interview with Mike Gousha at Marquette Law School.

"I made that pledge for that term," Feingold said. "What I did not anticipate was that the U.S. Supreme Corut would take all our campaign finance laws and throw them in the garbage can."

Feingold says now that the Supreme Court decision on Citizens United required him to change course. Whether Wisconsin voters interpreted the pledge this way is in the eye of the beholder.

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