Chancellor Angela Merkel’s conservatives won a regional election in the western state of Saarland on Sunday, dealing a setback to their Social Democrat rivals and boosting her prospects of winning a fourth term in Germany’s Sept. 24 national election. Merkel’s Christian Democrats (CDU) strengthened their position as the largest party in the state despite expectations ahead of the vote that the Social Democrats (SPD) would be boosted by their new national leader, Martin Schulz. The CDU won 40.1 percent of the vote, up from 35.2 percent in the last election in Saarland in 2012, an exit poll for broadcaster ARD showed. The SPD slipped to 30.1 percent, down from 30.6 percent.