You could make a massive list, quite frankly it doesn't mean much at this point. America is at a cross roads, especially economically. The massive debt that has accumulated is a National Security threat, it is going to leave the greatest democracy on earth beholden to other nations, many which are NOT democracies.
I find it confusing that many will suggest that global warming is a great threat, but Americas debt isn't. Borrowing from future generations, citizens who have no say in the matter is wrong, certainly as a perpetual policy.
Drastic times call for drastic measures. America will make friends and maintain allies with those nations who are legitimate allies. No more cowing to International nations who have no interest in global peace or individual rights. No more allowing foreign governments to steal Americas future.
Trump is certainly imperfect, but for the task at hand he may just be the president the America needs.