And a fat lot of good that did to them. They’re now more unpopular in Bavaria than they’ve ever been and there’s a state parliament election coming up. The CSU are used to getting more than 50% of votes, and that is really unlikely to happen right now.
For all the talk about refugees, the refugees aren’t the most pressing problem in German politics right now. Parties like AfD and CSU who are trying to keep the refugee issue front and center do this because they don’t really have anything worthwhile to say about anything else (AfD, not that they have anything worthwhile to say about refugees, either) or they’re trying to pass themselves off as the “like the AfD, but nice and electable” party (CSU). On the whole that doesn’t seem to be working all that great.
In fact, the worst thing that could happen to the AfD right now is to become the majority party in one of the state elections, because they literally would not know what to do with themselves. They’re quite happy being an opposition party since that lets them be against everything and bog down the government with useless and obnoxious questions. They would have to gain the absolute majority in a state in order to govern, anyway, because so far nobody wants to be in a coalition government with them – although it would be interesting to see what happens if the AfD gets the most votes in, say, Saxony but not enough to form a government on its own.