ST. PAUL — Longtime Rep. Paul Thissen joins an already crowded field of DFL candidates for governor.

Thissen plans to formally launch his campaign Thursday to replace Gov. Mark Dayton, who decided against a third term. He’s in his eighth two-year term representing southwest Minneapolis.

Thissen joins U.S. Rep. Tim Walz, state Reps. Erin Murphy of St. Paul and Tina Liebling of Rochester, St. Paul Mayor Chris Coleman and state Auditor Rebecca Otto in the race so far. Attorney General Lori Swanson is also said to be contemplating a run.

Thissen became speaker in 2013 when the DFL had a lock on state government with the Legislature and Dayton in control. But House DFLers lost their majority in 2014 and additional seats in 2016, leaving party leaders concerned about the 2018 election.