Bernie had as good a chance as a young inexperienced Black man, for they both promised change, which is what Trump promises.
Trump was not jubilant because he was probably on his meds. It also might have dawned on him that being president will actually be a very difficult job and he'll have to work very hard for the next four years to accomplish anything or go down in complete disgrace.
Eisenhower might not have been a politician, but he was obviously familiar with politics, the military, and the government. I would not put Dwight and Donald in the same category. I don't think (or hope) Donald is egotistical enough to think he can do the job himself.
Also, don't underestimate the impact of the state of the economy. While I can understand why you might say it is not that dire. The reality is that all the growth has gone to the people at the top, and the masses are increasingly worse off.
Think of it this way; there are more websites and more people online than ever before, but much of the wealth generated, as a result of this growth, is going to fewer websites. This creates oligarchic conditions which is resulting in most websites being worse off--despite the overall growth. Fewer websites are sharing the benefits of this growth. Because fewer websites are benefiting, people are worse off because they have less choice. This is the American economy.