Rep. Sean Duffy will resign from Congress effective September 23. He made the announcement in a Facebook posting Monday morning, citing family issues. The five-term Republican represents Wisconsin's 7th congressional district. It is the state's largest district by area, covering much of the northern half of the state.

Duffy was preceded in Congress by Democrat Dave Obey, who served over 40 years before retiring in 2010. Duffy won that year by 8 points over Democrat Julie Lassa. The district was made more Republican in 2011 post-Census redistricting, leading to fairly easy reelection races for the incumbent. He won his final term by about 22% in 2018, about the same winning margin as President Trump over Hillary Clinton in 2016.  

Wisconsin's Democratic Gov. Tony Evers will call a special election to fill the upcoming vacancy.