Chancellor Friedrich Merz’s mainstream conservative party has been trounced by the far right in recent state elections. His unpopular economic policies and gruff manner have failed to sway voters turned by rivals’ promises of easy fixes.

Mr. Merz is trying to enact difficult economic policies, including painful pension cuts, when voters want simple and painless solutions. He also struggles to explain them, especially to Germans under 25, for whom social media has replaced church, civic and political groups as the primary source of political information.

In Saxony-Anhalt and Mecklenburg-West Pomerania, young voters broke heavily toward the far-right Alternative for Germany, or Af D. In Berlin, they embraced the far-left Die Linke. Mr. Merz’s Christian Democratic party lost in all three elections and failed in Mecklenburg-West Pomerania to clear the 5 percent threshold.

Mr. Merz accepted some blame this week, vowing to stay in office and change. Analysts point to anger at fuel prices and his gruff communication style. His ratings have plunged toward single digits.