Duffy cited the upcoming birth of a child in October with a heart condition as his reason for stepping down early. Sean Duffy and his wife Rachel Campos-Duffy have eight children.
Rep. Sean Duffy (R-Wis.) will resign from Congress at the end of September, the most recent in a string of Republicans who have decided against running for re-election.
Duffy, who was elected in 2010 during a GOP wave, said he and his wife are expecting a child in late October who will "will need even more love, time, and attention due to complications, including a heart condition."
Duffy will leave Congress on Sept. 23. Duffy's district, anchored in the northern reaches of Wisconsin, has been solidly Republican in recent years. Duffy won re-election by 22 points, and Donald Trump won the district by 21 in 2016.