Now, more than 15 months after former President Donald J. Trump lost the state by 20,682 votes, an increasingly vocal segment of the Republican Party is getting behind a new scheme: decertifying the results of the 2020 presidential election in hopes of reinstalling Mr. Trump in the White House.

Wisconsin is closer to the next federal election than the last, but the Republican effort to overturn the election results here is picking up steam rather than fading away — and spiraling further from reality as it goes. The latest turn, which has been fueled by Mr. Trump, bogus legal theories and a new candidate for governor, is creating chaos in the Republican Party and threatening to undermine its push to win the contests this year for governor and the Senate…

In Wisconsin, the decertification push has Republican politics on its head. After more than a decade of Republican leaders marching in lock-step with their base, the party is hobbled by infighting and it’s Democrats who are aligned behind Gov. Tony Evers, who is seeking a second term in November.

“Republicans now are arguing over whether we want democracy or not,” Mr. Evers said in an interview on Friday.