Mr. Söder, who holds regular citizens’ office hours to hear from voters directly, has made it his mission to lure back voters from the AfD, which has been gaining ground in Bavaria ever since its 500-mile land border with Austria became the main gateway for migrants into Germany in 2015 and 2016.

Though the number of new arrivals is back to pre-crisis levels, Mr. Söder, sounding a lot like the AfD, is warning that Germany’s migration crisis is coming back and that vast areas of the country have already become lawless no-go areas.

“People expect the state to show strength,” he said in an interview before his recent beer tent appearance. “Migration and the question of cultural identity have posed a new question and you can’t answer that with old recipes.”

His new recipe — ahead of hard-fought state elections in the fall — includes a striking disregard for facts. He sides with President Trump (rather than official German crime statistics) when he claims that migration is producing a crime wave. In fact, crime in Germany is at a 25-year-low.

Lies, Mr. Söder scoffs.

“We have whole cities where law and order has withdrawn from neighborhoods,” he said, citing Berlin and cities like Duisburg in the old industrial heartland in northwestern Germany.

“How can the state judge crime statistics in Duisburg when there are no police anymore?” he said.

He also rejects the notion that the actual migration crisis has subsided. In 2016, when the numbers reached their zenith, more than 62,000 people sought asylum in Germany on average every month. This year, that average has fallen to little more than 15,000 — the lowest since 2013. And the number of those registered elsewhere in Europe amounts to only a few hundred so far this year.