If I hear one more ignorant idiot tell me "But, the president is exempt from conflicts of interests..." I'm going to blow my top. We have a constitution in this country and the 45th president has been in flagrant violation of that document since the moment he uttered the oath of office.
I want to emphasize his impeachable offense (aside from new accusations of treason) and why It's not so much about the conflicts of interest as it is about his business receiving any kind of payments (including trademark deals) from foreign states.
US Constitution Article 1, section 9, Clause 8 "No title of nobility shall be granted by the United States: and no person holding any office of profit or trust under them, shall, without the consent of the Congress, accept of any present, emolument, office, or title, of any kind whatever, from any king, prince, or foreign state."
Emolument is the key word here as it means a fee for a service. The origin of the word itself is a miller's fee for grinding grain. Therefore, the second he took the oath of office he was in violation of this little-known corner of the constitution as I am sure somewhere on planet earth a dignitary of some foreign state had either paid or was about to pay a fee (emolument) for staying at one of his properties.
Now, congress could give him permission to receive such payments, but I do believe they would not grant said permission as they would pay the political price for doing so at some point. I hope this explanation clarifies why I keep railing on this point. Call me an armchair legal expert if you like but my main source on this is Richard Painter - former chief ethics attorney for George W. Bush.