Yes, they can do whatever they want, however, if they choose to be a publisher they cannot be afforded section 230 protections. You're entirely free to ban political speech you disagree with, however, you must be held liable for the content you allow — for that which was removed was done so without good faith.

Also, I don't support Trump. You're the idiot for assuming I do. But I can infer from your language that your words are not your own, but rather manufactured by your employer. I do not blame you for being a shill — you need to make ends meet — but I do pity you.