"I am done," Gauthier, DFL-Duluth, said Wednesday. "I just need to take care of myself right now and I am not really up for that kind of fight."
Gauthier, 56, admitted to police he had oral sex behind a highway rest stop July 22 with a 17-year-old boy he met after he placed an advertisement on the Web site Craigslist.
The St. Louis County, Minn., Attorney's Office decided last week not to press charges against Gauthier because Minnesota's age of consent is 16 and that authorities were told the sex was consensual and no money had been exchanged, the Star Tribune newspaper in Minneapolis said Thursday.
Gauthier's decision to leave the race came after a day of persuasion from the state's Democratic Farmer Labor Party, Minnesota's affiliate of the Democratic Party, urging him to bow out of a race in a Duluth, Minn., district seen as a DFL stronghold.
"I fully support his decision, which brings to an end an unfortunate chapter," said state House Majority Leader Paul Thissen, DFL-Minneapolis.
The DFL faces an uphill battle to retake control of the state's House of Representatives and the Republican Party was prepared to make Gauthier the face of the DFL, the newspaper said.