I think the biggest detriment to Trump as president is his inability to hold up the United States as a world leader - the president isn't as important domestically for policy (which we have discussed many times previously and generally agree upon, as I recall), but is far more important for foreign policy. I'll give Trump some due - he has gotten China to sign on to greater sanctions on North Korea, and scared some of Europe into increasing military spending to NATO. But overall he's not very well regarded by pretty much any other G20 leader, his decision to attempt to renegotiate NAFTA may lead to the end of the agreement, and I don't think anyone considers him and thus the US to be a leader out of anything other than raw military power. That makes working with the US internationally quite difficult.