As for CSU being a loser: It is the only party in Germany that is in absolute majority in a state parliament:
https://en.wikipedia.org/wiki/States_of_Germany
As for the result of the FEDERAL election in 2017 in Bavaria, this is complicated by the drift to the center of Merkel.
FDP and AfD did well in Bavaria, and FW got 3.7 percent of the vote with no chance of entering the Federal parliament.
To remain the dominant party of Bavaria, CSU must shore up its position on the right. This aspect of local politics is reflective of CSU’s negotiating position with Merkel at this time. But, in this age of splintering of parties, it wouldn’t be embarrassing for CSU to win next year’s state election with “only” 40 percent of the vote.
LOL - CSU got it hind whupped because Seehofer steered it wrong into intolerance & zenophobia and away from its Christian traditions.
Franz Josef would have never allowed himself to be outmanuvered by amateurs wack jobs like the AfD.
The CSU trajectory has been steeply downhill for a long time. It’s become a party of dinosaur party hacks, not leadership.
Unless they change their leadership at next months party congress to someone modern like the young economics minister, they are going to get crushed in Sept.
CDU is also ready to chuck the loser CSU.