Conservatives and Republicans in Minnesota are objecting to Democratic Rep. Rick Nolan putting on a fundraiser featuring an appearance by the Peter, Paul and Mary singer who pleaded guilty years ago to taking "immoral and indecent liberties" with a 14-year-old girl.

Peter Yarrow pleaded guilty to the crime in 1970 and served three months in prison. President Jimmy Carter pardoned him in 1981.

Per the Minneapolis Star Tribune, the event will take place April 25 at Bowery Brothers Pub in Duluth.

“I'm really offended that he would even consider associating himself with someone that demeaned and molested a young woman,” said Laura Johnson, the secretary of the Wadena County Republican Party. “It was really disappointing when I heard that he was doing that, and I think that he should call off the fundraiser.”

Alexandra Boettcher, a conservative activist and former College Republicans chair who attends the University of Minnesota Duluth, said she found the move baffling.

“It’s really insulting to women to have him parading around with someone who was convicted of molesting — not just molesting a woman, but a 14-year-old girl,” she said. “It’s just really unfortunate that he would think this is OK.”

Nolan, who is running for his second term since returning to the House (he represented Minnesota for three terms in the 1970s), is being challenged by Republican Stewart Mills. The race is being closely watched, and Nolan is considered to be one of the more vulnerable Democrats on the ballot this election cycle.

The National Republican Congressional Committee is calling for Nolan to cancel the fundraiser.

“Rick Nolan should immediately cancel his fundraiser with a convicted child molester and apologize to his constituents,” said Tyler Houlton, an NRCC spokesman. “The fact that Rick Nolan even considered hosting an event with a child molester in the first place shows how wildly out of touch he is with Minnesota families.”

Brandon Lorenz of the Democratic Congressional Campaign Committee told the Star Tribune the following: "This is a desperate attempt from Stewart Mills to distract from the fact that he is personally offended when millionaires like himself are asked to pay their fair share."

Nolan’s campaign did not immediately respond to a request for comment.

Among Peter, Paul and Mary's biggest-selling hits were "Leavin' on a Jet Plane" and "Puff, the Magic Dragon." The group has long been politically active, performing at the original 1963 March on Washington and taking part in the anti-war movement during the Vietnam War period. Mary Travers died in 2009.

This isn’t the first time Yarrow’s activism has caused problems for Democrats. In 2004, Rep. Martin Frost of Texas cancelled an appearance with him after drawing criticism from Republicans. He lost that election to Pete Sessions.

And in September 2013, Republicans called for New York Democratic congressional candidate Martha Robertson to cancel a fundraiser with Yarrow.