The far-right Alternative for Germany was projected to win a strong victory in a regional election Sunday, but it wasn’t immediately clear whether it would be able to fulfill its ambition of forming the country’s first far-right state government since World War II. The party of German’s unpopular leader, Chancellor Friedrich Merz, was set for a disastrous result in the eastern state of Saxony-Anhalt. The anti-migration and Russia-friendly Alternative for Germany’s candidate for governor said that “we have written history.” Ulrich Siegmund, 35, told public broadcaster ARD that voters had sent a signal that “things cannot carry on like this” and...