When the Florida Legislature begins its annual session on Tuesday, Gov. Ron DeSantis will be on hand — fleetingly. After giving his State of the State address, he will leave for Iowa, where he has a packed campaign schedule ahead of the Republican presidential caucuses on Jan. 15. Few in Tallahassee expect to see much of him in the months that follow.

His absence will be a conspicuous change from the last few years, when Mr. DeSantis loomed large over the Legislature, his every major wish granted by friendly lawmakers. The Republicans who control both chambers were eager to curry favor with the state’s political superstar, who seemed poised to lead their party’s presidential field.

Instead, Mr. DeSantis’s presidential bid has struggled. His pitch to make America more like Florida has lost much of its fizz, with the frenzied culture wars that have gripped the state proving less appealing to a national audience. To date, the governor has lagged far behind former President Donald J. Trump in the polls.

Mr. DeSantis’s job approval among Floridians has dipped, polls show. He remains a powerful figure, able to destroy lawmakers’ dreams with his veto. But everyone in the Capitol knows that Mr. DeSantis is not as invincible as he once seemed.

“If he were the front-runner in the presidential race, things would be very different,” said State Representative Fentrice Driskell, a Tampa Democrat and the House minority leader. “He’s finding out that all these culture wars that he fought for in Florida aren’t winning him votes.”

So lawmakers have prepared for a different kind of session, one that could feel like a breather after Mr. DeSantis’s resolve over the last two years to reshape state policies in eye-catching ways that he hoped would appeal to Republican primary voters.