Maryland Democratic senator Ben Cardin announced he is not seeking re-election in 2024, sparking a competitive Democratic primary. 

The 79-year-old has been serving in the Senate since 2006. He broke the news to hometown newspaper The Baltimore Sun, saying he's ready for retirement.

“I always knew this election cycle would be the one I would be thinking about not running again, so it’s not something that hit me by surprise," he said.

Senate Democrat to resign

Cardin's move isn't likely to change much in 2024, given Maryland's reliably blue lean. No Republican has won a U.S. Senate election in Maryland since 1980.

But Democrats are facing a heavily unfavorable Senate map next cycle, with vulnerable seats in Trump-friendly states like Montana and West Virginia.

Senate Majority Leader Chuck Schumer (D-Ny.) called Cardin "one of my dearest friends in the Senate."

A true public servant, @SenatorCardin's made meeting the needs of Marylanders his life’s work.

One of my dearest friends in the Senate, I always admire him for favoring substance over flash, digging deeply into issues, his ability to persuade others of the justice of his causes. https://t.co/3a0feBXsGr

— Chuck Schumer (@SenSchumer) May 1, 2023

Potential successors have already begun jockeying for position, including George’s County Executive Angela Alsobrooks, Rep. David Trone (Md.), Baltimore County Executive Johnny Olszewski Jr., and Rep. Jamie Raskin (Md.).

Horse race begins

Raskin, who is suffering from cancer, praised Cardin for a "career devoted to service of our people and the old-fashioned public values of honesty and decency." Raskin has built a national profile with his role in the January 6th hearings.

Cardin has mostly avoided the spotlight during his time in office, earning a reputation as a bi-partisan pragmatist. He chairs the Senate Small Business Committee.

“I was taught that it’s okay to compromise — don’t ever compromise your principles — but find a path to get things done. Inspire trust in those around you. Keep your word and, again, listen,” Cardin said in a statement.

Before serving in the Senate, Cardin was a House representative for 20 years. He is the third Senate Democrat to announce retirement in 2024, joining California's Dianne Feinstein (D) and Michigan's Debbie Stabenow (D).

Like Cardin's seat, Feinstein's is a shoo-in for the Democrats, so a brutal primary is likely. Michigan is more competitive territory.