Rep. Tom Petri will not seek reelection
© Greg Nash

Rep. Tom PetriThomas (Tom) Evert PetriBreak the cycle of partisanship with infant, child health care programs Combine healthcare and tax reform to bring out the best in both Overnight Tech: Internet lobby criticizes GOP privacy bill | Apple sees security requests for user data skyrocket | Airbnb beefs up lobbying MORE (R-Wis.) will announce Monday that he is retiring, opening up what could be a competitive House district. 

“U.S. Representative Tom Petri (R-WI) will make a statement on Monday, April 14, at his town hall meeting in Neenah, Wisconsin, announcing that he will not be a candidate for reelection to Congress,” his office said in a Friday afternoon statement.

Petri, 73, has served in Congress since 1979. 

Republicans had already been lining up to run against the longtime congressman, who some had speculated might retire. Wisconsin state Sen. Glenn Grothman (R), a favorite of conservatives, had already announced a challenge against Petri.

Wisconsin state Rep. Duey Stroebel (R) and businessman John Hiller, a confidante of Wisconsin Gov. Scott Walker (R), have also been quietly mulling bids. State Sen. Joe Leibham (R) has also been mentioned as a possible candidate if Petri retires.

After the news broke Friday, Liebham said on Twitter "I appreciate your thoughts and prayers as I contemplate a candidacy for the 6th Congressional District. Stay tuned for more news."

Democrats could have a shot at winning the slightly Republican-leaning suburban Milwaukee seat, especially if Republicans nominate a hardline conservative for the race. In 2012, GOP nominee Mitt Romney won the district in with 53 percent, but Obama carried it in 2008 by just 651 votes.

Wisconsin Democrats mention Manitowoc Mayor Justin Nickels (D), a young rising star in the party, and former state Sen. Jess King (D), who won a hard-fought election to recall a Republican state senator following Walker's push against unions, as potential candidates who are considering a bid.

Petri is the latest in a string of Republicans retiring from swing or Republican-leaning districts. 

He joins Reps. Dave Camp (R-Mich.), Mike Rogers (R-Mich.), Jim Gerlach (R-Pa.), Tom Latham (R-Iowa), Buck McKeon (R-Calif.), Gary Miller (R-Calif.), Jon Runyan (R-Va.) and Frank Wolf (R-Va.) as members whose retirements give Democrats at least an outside shot of winning their seats, though the national climate isn't shaping up to make this a great year for Democrats to target the seats.

Petri's decision also comes after he requested an ethics investigation in mid-February of his own actions.

A letter he wrote to the House Ethics Committee said he was “distressed by the innuendo” that there is a conflict between his personal financial interests and his official actions in Washington.

"To end any questions, I am requesting that the committee formally review the matter and report back," the letter read. 

Two news outlets had previously reported that Petri had promoted the services of defense contractor Oshkosh Corp. to the Pentagon, based in his district, when he had invested hundreds of thousands of dollars worth of stock in the company.

In the late 1980s, Petri participated in the ethics investigation that led to the resignation of then-House Speaker Jim Wright (D-Texas).  Petri had served as a member of the Committee on Standards of Official Conduct, which is now the House Ethics Committee.

Petri serves on the House Transportation and Infrastructure Committee and Education and Workforce Committee.

This post was updated at 5:35 p.m.