Stabenow's surprise retirement pushes Michigan closer to center of 2024 Senate map

Michigan Democratic Sen. Debbie Stabenow announced Thursday that she will retire at the end of her term, opening up her seat in 2024 and moving her battleground state closer to the heart of the Senate map in two years, when her party will be on the defensive in retaining its narrow majority.

Stabenow, who was first elected to the chamber in 2000 and is a member of Democratic leadership, said in a statement that as she leaves office in January 2025, she will look to hand power to younger lawmakers while she returns to private life.

She said she intends to spend "precious time" with her family, including her 96-year-old mother.

"Inspired by a new generation of leaders, I have decided to pass the torch in the U.S. Senate. I am announcing today that I will not seek re-election and will leave the U.S. Senate at the end of my term on January 3, 2025," she said.

Her announcement, which surprised Democrats from Lansing to Washington, spurred immediate speculation over who could run for her seat in a swing state where Democrats have seen recent successes after Donald Trump narrowly flipped it in the 2016 presidential election.

To run a replacement for Stabenow, Democrats boast a particularly deep bench in Michigan, including several incumbent federal and statewide officeholders.

Reps. Debbie Dingell, Dan Kildee, Elissa Slotkin and Haley Stevens, Lt. Gov. Garlin Gilchrist, state Secretary of State Jocelyn Benson, state Attorney General Dana Nessel and state Sen. Mallory McMorrow were all mentioned by observers as Democrats who could potentially launch a campaign to succeed Stabenow.

Gov. Gretchen Whitmer, who had a double-digit win in last year's midterms, and Transportation Secretary Pete Buttigieg, a former presidential candidate who moved his residency to Michigan, were also included in the rumor mill though both put out statements downplaying any interest in running for the Senate.

Democrats have recently enjoyed success in Michigan despite its battleground status, with Whitmer winning reelection and the party winning both chambers of the state legislature in November.

Still, Stabenow's decision to retire is likely to complicate the party's strategy in the 2024 congressional elections, when they face a daunting Senate map.

Beyond defending seats in swing states like Arizona, Nevada, Pennsylvania and Wisconsin, Democrats will also need to hold onto seats in Montana, Ohio and West Virginia, all three of which typically elect Republicans.

In total, Democrats will have 23 Senate seats up for reelection compared to 10 for the GOP.

With a 51-49 Democratic advantage in the Senate, their current majority is two seats, given that Vice President Kamala Harris can break ties.

The fragility of that hold was put into sharper relief Thursday after Sen. Bob Casey, D-Pa., whose seat is also up in 2024, announced he had prostate cancer, though he said in a statement that he should be able to continue his work "with minimal disruption" and touted his prognosis.

In Michigan in particular, Stabenow, who's held various offices since 1975, loomed large among her colleagues.

"We all thought she was running," one former state legislator said in a text to ABC News. "She was unbeatable. A total beast in the state."

The Democratic Senatorial Campaign Committee (DSCC) contended that it would still be able to defend Michigan without Stabenow in the race.

"In 2022 Michigan Democrats won resounding statewide victories, and we are confident Democrats will hold this Senate seat in 2024," DSCC spokesman David Bergstein said in a statement.

Among those Republicans who could launch a Senate bid in two years are former Rep. Peter Meijer, who lost his primary last year to a Trump-backed challenger; incoming Rep. John James, who previously lost two Senate bids; Tudor Dixon, who lost her challenge to Whitmer; former state Attorney General Bill Schuette and more.

"We are going to aggressively target this seat in 2024. This could be the first of many Senate Democrats who decide to retire rather than lose," National Republican Senatorial Committee Communications Director Mike Berg said in a statement.

Republicans could face a messy primary depending who in their party runs for the Senate, given that some conservatives in the state are close allies of former President Donald Trump -- and some, like Meijer, have vocally opposed him.

"Great opportunity. Tough state," tweeted Steven Law, the head of Senate Leadership Fund, Senate Republicans' top super PAC. "Needed: a candidate who can raise money, unite the party and appeal to GOP-leaning Independents."