Polling stations have opened for two German regional elections that could impact Chancellor Friedrich Merz's hold on power. The elections are taking place in Mecklenburg-Western Pomerania and Berlin. The far-right Alternative for Germany, or AfD, is expected to gain ground. Sunday's vote comes two weeks after AfD's strong performance in Saxony-Anhalt. Merz's center-right Christian Democratic Union party faces challenges, especially in Berlin. Merz, who became leader 16 months ago, has struggled with economic reforms and popularity. Despite calls for his replacement, he says he's determined to finish his term.