Ban the AfD now
Many argue the AfD is openly anti-constitutional and Germany's 'wehrhafte Demokratie' exists precisely to ban such parties; the leak adds evidence and CDU/CSU hesitation is the main blocker.
Banning parties is undemocratic or futile
Others say banning a party polling 25-40% looks authoritarian, would backfire, and ignores the unaddressed voter concerns, especially immigration, that fuel its rise.
Center-right will normalize the far right
A recurring worry is that conservatives will copy AfD messaging and eventually govern with them, as seen elsewhere in Europe and the US.