Minnesota Senate Majority Leader Kari Dziedzic, who led the 34-member DFL caucus through a historic 2023 session, stunned fellow senators Friday by announcing she will step down from the leadership post to focus on her cancer treatment.

"Unfortunately, in the last week, I learned that my cancer has returned, and I am facing some serious challenges," she said in a written statement. "As we prepare for the next session, I decided it is in the best interest of the caucus for me to step down as majority leader after our caucus has selected a new leader."

The development comes 10 days before the 2024 Legislature opens and was a surprise in part because of how Dziedzic, 61, successfully juggled major surgery, cancer treatment and last year's session. She told fellow senators of her decision in a noon online meeting and simultaneously released an email to staff and the media.

The news saddened her colleagues.

"As a freshman, she almost instantly became my mentor," said Sen. Heather Gustafson, DFL-Vadnais Heights, who flipped her northeastern suburban district from red to blue in 2022. "I can't tell you how many late nights I've been on the phone with her.

"She really took me under her wing. I just love her so much."

Gustafson said both she and Dziedzic are workaholics who found plenty of laughs amid the stressful 2023 session.

Gustafson and other senators praised Dziedzic's leadership last year as the DFL passed a long list of progressive policy changes with only a one-vote edge over the chamber's Republicans.

Senate Tax Committee Chair Ann Rest, DFL-New Hope, called Dziedzic the best negotiator in the caucus. "I can be hopeful that others could have done as a good a job as she has done keeping us together, but I think she's unique and I hope that going forward we learn from that," Rest said.

Dziedzic is a five-term senator deeply rooted in northeast Minneapolis. While her father, the late Walt Dziedzic, was a garrulous, occasionally bombastic, member of the Minneapolis City Council and the city Parks Board, his daughter is much quieter, not prone to showing emotion, delivering pithy quotes or stepping into the spotlight to claim credit.

When the Senate flipped to the Democrats in November 2022, she was an unexpected choice for majority leader.

The following month, a routine health screening detected cancer. In March, she underwent a hysterectomy and her appendix and spleen were removed. During that time, she led the Senate and voted remotely during lengthy floor sessions.

The DFL held together through difficult votes on gun safety measures, expanded abortion access, marijuana legalization, the restoration of voting rights for felons and making Minnesota a refuge for transgender residents.

"She's awesome. She really is," said Sen. Matt Klein, DFL-Mendota Heights. "We had a majority of one, and we passed the most incredible agenda. Nobody thought we could do that. She gets full credit; she listens to everybody."

Dziedzic returned to the Capitol in May as the session wound down. The only sign of her cancer battle was a new wig and weight loss.

"My unexpected cancer diagnosis complicated the busy 2023 session but did not slow down or divert us from our focus. Senate DFL members and staff stepped up and worked as a team," she said in her statement Friday. "We were strategic, finished on time, and passed wide ranging legislation to help Minnesotans across this great state."

Until they heard the news, most of her caucus members said they were hoping this year would be easier for Dziedzic with a far less ambitious legislative agenda and the cancer behind her.

"We all thought this would be a much better session for her," Gustafson said.

Assistant Majority Leader Nick Frentz, DFL-North Mankato, said, "Our caucus is numb, and we will press on as we have done many times in the past, but she's our leader."

Frentz said senators have met many times to prepare for the coming session. "And now we need another one" to choose a new leader, he said.

Neither Frentz nor the other senators would discuss a possible successor, but obvious possibilities among current leaders include Frentz and Senate President Bobby Joe Champion, another Minneapolis DFLer who is close to Dziedzic.

In an interview, Champion declined to comment on the speculation. He instead turned attention to his written statement in which he said Dziedzic's career has been defined by her one-of-a-kind leadership skills.

"Her decision to step down from her post of majority leader is reflective of her selfless leadership style," he said, adding that she will continue to play an important role in the Senate DFL.

Champion earned widespread praise last session as he stood at the front of the chamber and managed windy, complicated debates. Champion would also be the first person of color to lead the Senate majority caucus.

Rest said, "We certainly want to have a seamless transition, and I think we all agreed on that."

Well-wishes for Dziedzic flowed from other Capitol leaders.

Republican Senate Minority Leader Mark Johnson of East Grand Forks said he's keeping Dziedzic in his prayers. "I wish her all the best as she takes care of herself and beats cancer again; I know she will," he said. "Her genuine friendship as a fellow caucus leader will be deeply missed."

House Speaker Melissa Hortman, DFL-Brooklyn Park, who worked closely with Dziedzic, conferring multiple times a day, said she was devastated by the news.

"Minnesota could not have asked for a better, more effective leader of the Minnesota Senate," Hortman said in a statement. "Her kind, thoughtful, and wise leadership brought the Senate through the most productive legislative session in 50 years.

"Beyond all of that, she's a great friend. I'm praying for her to receive excellent health care and to return to full time legislating as soon as possible."