The KPD in particular got banned for wanting to topple the government by force, also, they took their orders from Stalin. Being a communist as such is far from anti-constitutional, the German constitution was specifically written to be compatible, but it’s going to have to be democratic market socialism. What you want to do is heavily lean on Article 14(2): “Property entails obligations. Its use shall also serve the public good.” You can expropriate means of production by mere preference, without having to show that it’s for the public good.
The KPD in particular got banned for wanting to topple the government by force, also, they took their orders from Stalin. Being a communist as such is far from anti-constitutional, the German constitution was specifically written to be compatible, but it’s going to have to be democratic market socialism. What you want to do is heavily lean on Article 14(2): “Property entails obligations. Its use shall also serve the public good.” You can expropriate means of production by mere preference, without having to show that it’s for the public good.