MADISON - One of the state's top Democrats is leaving her post in the state Senate — retiring after leading her party in the state Capitol during one of the most consequential decades for Wisconsin politics.

Jennifer Shilling of La Crosse, the Senate's minority leader, will retire at the end of her term this year — likely triggering a leadership overhaul in both caucuses as her GOP counterpart makes a bid for Congress.

"It was not an easy decision, but I know it is time to put my family first and look to a future where I can put away my little red suitcase that has accompanied me on my weekly travels to Madison for the past 20 years," she said in a statement. "I do not leave with regrets, I leave with wonder — wonder about the future, about what will be. Wonder about what lies ahead, and a wonder of new ways that I will continue to be able to serve my community, and others."

Shilling, 50, will leave the state Senate in a similar way she arrived: during massive economic uncertainty. Tumult, she has said, shaped her approach to working with colleagues, by making peace offerings whenever she can — "Chex Mix diplomacy," she calls it, referring to her proclivity for sharing large batches of the homemade treat to lawmakers from both parties.

"I came into the Senate in 2011 and it was a tough time so civility is one thing I've really tried to practice and demonstrate with my colleagues," she said in a January 2019 interview with The Capital Times.

Shilling spent more than a decade in the state Assembly and won a seat in the Senate in 2011 as part of a wave of recall elections over Act 10, the state law that greatly limited collective bargaining for public workers.

The election came as Wisconsin and the U.S. were digging out of the Great Recession, prompting Republicans to pass the legislation that made massive cuts to school funding that was offset by school staff paying more toward pensions and health insurance after the passage of Act 10.

That legislation also decimated Democrats' coffers during the time Shilling has served in the Senate.

But Shilling has overseen some of the party's wins in that time, too. She twice took on and defeated longtime Republican Sen. Dan Kapanke. Kapanke is making another run for the seat this year.

And it was Sen. Patty Schachtner's win in the 10th Senate District in northwestern Wisconsin in a January 2018 special election that gave Democrats momentum heading into the fall election that year, during which Democrats swept all statewide offices.

Sen. Jon Erpenbach, D-West Point, said Shilling was a hard worker who recruited great candidates for Democrats during challenging times.

“She was exactly the right person for our caucus at the right time,” Erpenbach said. “We had a fractured caucus somewhat. She pulled us together.”

Her departure will be the fourth high-profile Democrat to leave the Senate. Joining her are Sens. Fred Risser of Madison, who has served in the Senate for 64 years, Dave Hansen of Green Bay and Mark Miller of Monona. Longtime Sens. Lena Taylor and Chris Larson also could leave should they win their respective races to lead Milwaukee city and county government.

Shilling calls herself a "bus stop mom" and often invokes those roots on the Senate floor to bring her colleagues down to earth, often urging everyone in the room to work together instead of against each other.

Shilling also is known for her sense of humor, at one point during a floor session on Halloween she dressed up as her Republican counterpart, Senate Majority Leader Scott Fitzgerald — complete with his signature red tie.

"We are in an arranged marriage here — honestly outside of this building we probably wouldn't even date each other," Shilling said in the 2019 interview, just weeks into the first term of divided government under Democratic Gov. Tony Evers and a GOP-controlled Legislature. "But we need each other — I'm hoping to find some common ground on issues and dial back the bombastic campaign rhetoric."

Shilling entered the Legislature after losing her parents in a brutal murder that captured national headlines. She has not talked often about her loss, but in 2019 spoke to the Milwaukee Journal Sentinel about the effect of that violence on her life in an effort to persuade her Republican colleagues to tighten gun restrictions.

"I am tired of knowing that pain. It is unspoken pain," Shilling said in September. "We don't have to use any words to talk about the pain that we have. ... For the Legislature, be it Congress or this institution, to do nothing is not acceptable anymore."

Shilling's seat will be tough, but not impossible, for Democrats to keep. It's part of the swingiest areas of Wisconsin. Voters there supported Presidents Donald Trump in 2016 and Barack Obama in 2012.

Shilling defeated Kapanke in 2016 by 56 votes.

Shilling's district is an area of western Wisconsin known as the Driftless Region, named after the area didn't experience glaciers smoothing its landscape like in other parts of the Midwest. In recent years, the area's small dairy farms have experienced an unprecedented downturn and destructive flooding.

"A broad smile, firm handshake, and kind words throughout the district brightened my day, as I listened to, learned from, and laughed with the hardworking people of western Wisconsin," she said. "From dairy breakfasts, community events, and business tours to parades, school visits, and disaster recovery efforts, you showed me what perseverance, ingenuity, and strength looks like."

Patrick Marley of the Journal Sentinel contributed to this report.

Contact Molly Beck at molly.beck@jrn.com. Follow her on Twitter at @MollyBeck.