A CDU/CSU alliance with the nationalist AfD would get them to 49% of the seats. The problem is that 1%; the AfD is even more repugnant to most of the socially liberal Free Democratic Party. But there is a euroskeptic faction. I would suspect a few FDP might jump ship to a CDU/AfD alliance, if only Merkel would push for it.
This is exactly what it’s all about-the AfD.
All other parties, I repeat, ALL other parties, have clearly stated they will never co-operate with AfD in any way.