Ben Wikler, who built the Wisconsin Democratic Party into a fund-raising colossus over his six years as its leader, is leaving his post in June.

Mr. Wikler, 44, said in an interview on Wednesday that he was considering running for office but would first spend time taking vacations with his three young children.

“The best time to pass the torch is when an organization’s on the upswing,” he said. “I’m able to step away from the party this June knowing that Democrats are poised to make enormous gains in Wisconsin.”

Mr. Wikler’s announcement comes a week after he oversaw a decisive victory in a Wisconsin Supreme Court election. Barring an unexpected vacancy, the result cements a liberal majority on the court until at least 2028. He will leave behind a state party with aspirations of winning full control of Wisconsin’s government in next year’s midterm elections — something that would have been just a dream when he took over in 2019.

At that time, Republicans had led both chambers of the State Legislature since 2011, and conservatives had controlled the State Supreme Court since 2008.

Now, Mr. Wikler — who wants Democrats to run a “permanent campaign” that never lets up — forecast a liberal resurgence in opposition to President Trump. He predicted that Democrats would win a governing trifecta in Wisconsin as they sweep elections across the country. The party now controls the governor’s office and the state’s top court, with Republicans holding on to majorities in the Legislature.