You mean enforcing section 230, but you are correct.

I’m curious how that would turn out? What would happen if Trump was banned? While I’m against censorship, banning someone for not following your “code of conduct” is well within your rights.

The best example is what happened when Alex Jones found himself deplatformed -- although I think the simplest answer there is "too little too late".

I'd guess Trump would move to a new platform, and take his social media circus with him. Twitter presumably wants to keep that traffic.