Since returning to Minnesota after a failed bid for vice president, Gov. Tim Walz has kept a relatively low profile. He consoled deflated supporters with a speech at a high school, posed for photos with a turkey at the Minnesota State Capitol to mark Thanksgiving and flew to the Bahamas for a brief respite from the cold.

This week, Mr. Walz, a Democrat, must start grappling in earnest with his party’s sinking political fortunes in his home state as lawmakers begin meeting in St. Paul for what is expected to be an unusually acrimonious state legislative session.

Minnesota Democrats controlled the governor’s mansion and the State Legislature the past two years, allowing them to pass a trove of liberal laws on abortion rights, marijuana and medical leave. But they are bracing for a new era of gridlock, having lost their slim majority in the House. Their control of the Senate is tenuous.

State budget officials last month issued a grim assessment of Minnesota’s fiscal health, warning that spending is projected to exceed revenue in coming years. The officials said a $5.1 billion deficit is possible by 2028. Under the Democrats’ leadership, the state had a $17.5 billion surplus at one point, leading critics to question how tax dollars have been spent.

“It’s going to be an arduous, hard, really tough session,” said Blois Olson, a political analyst and communications strategist in St. Paul. A looming question in St. Paul is whether Mr. Walz will seek a third term in 2026 after what many say they anticipate could be a bruising return to his state duties during the legislative session. “If he feels beat up after that,” Mr. Olson said, “I think his prospects of running again are going to be low.”

Shortly after Mr. Walz returned from the national campaign trail in November, signs arose of new tensions at home. Mr. Walz was not seen at public events with his lieutenant governor and running mate, Peggy Flanagan. Reports of a falling out over preparations for a potential succession plan for the governor’s job — in the case of a Democratic win of the White House — spilled into the open.