Republican Michael Alfonso, the son-in-law of Transportation Secretary Sean Duffy, won Wisconsin’s 7th Congressional District on Tuesday — clinching the same seat his father-in-law once held.

Alfonso beat Democrat Fred Clark, a former state lawmaker, 56% to 44% with nearly all the ballots tallied.

“Michael will be the youngest member of the new Congress & the first one born in this century,” Rachel Campos-Duffy, his mother-in-law and Fox News personality, posted. “Go Gen Z!”

The win will make Alfonso, at 26, the youngest lawmaker on Capitol Hill in January. It’ll also make his wife Evita — Duffy’s eldest daughter — a congressional spouse.

Alfonso will take the title from Florida Democratic Rep. Maxwell Frost, who is 29.

Duffy, the MTV “Real World” alum turned congressman, won the remote Northwoods district in the 2010 Tea Party Wave. He ended four decades of Democratic control over the seat that dated to Dave Obey’s first election in 1969.

He served until 2019, when he resigned ahead of the birth of his ninth child, who had a heart condition.

Alfonso grew up in the 7th District and graduated from the University of Wisconsin-Madison. He worked in construction and produced Dan Bongino’s podcast before launching his campaign in October 2025, pitching himself as the voice of zoomer Wisconsinites.

President Trump endorsed him in January, calling him a “MAGA Warrior.”

The road to the Republican nomination was not smooth. Alfonso’s chief primary rival was Kevin Hermening, a former Marine held hostage in Iran for over a year. Hermening went on to spend decades chairing the Marathon County GOP — and helped elect Duffy himself.

Alfonso beat the veteran with Trump’s endorsement and $1 million from his father-in-law’s dormant campaign account, routed through a super PAC, according to PBS Wisconsin.

Delta Air Lines — whose planes cannot leave the gate without the blessing of the department Duffy runs — was among the sponsors of a December fundraiser where Duffy was billed as a special guest, according to ProPublica. Delta’s PAC also gave Alfonso’s campaign $5,000.

The Transportation Department said Duffy supported Alfonso only in a “personal capacity.”

Alfonso won the five-way August primary with about 48% of the vote.

Clark, 67, is a former state legislator and forester from Bayfield. He ran as a self-proclaimed “independent-minded” Democrat and argued the race was district’s first real contest in 15 years.

Alfonso will succeed Rep. Tom Tiffany (R-Wis.), who gave the seat up to run for governor but lost to Democrat David Crowley.