I do think he is an able negotiator, and if he were dealing at arm's length and in good faith, he would be a splendid politician. But in dealing with the elite that controls our government, the people on the other side will not be dealing in good faith. He will be compelled to "act because Congress has not acted," or be impotent. My assessment of his presidency is based on how I think he would choose in that scenario.
Don't get me wrong here; the situation we have is not entirely one of the President grabbing unconstitutional powers. The opportunity was handed to 0bama (deliberately by Harry Reid) because Congress is dysfunctional. The dysfunction in Congress is mainly political, and by that I look at three aspects of public office in the United States; politics, policy and law.
Politics is what you do to gain office, and is supposed to be the input or means of the people to express their voice by the selection of elected officials. Policy is what those officials pursue once they have gained office. Theoretically, it is the expression of the political will of people who put them there. Law is what is created to carry out that policy. Law is to be carried out by the executive, and interpreted by the Courts. The executive should only make policy as necessary to carry out the law. Courts should never make policy.
Our system has broken down in so many ways I can't post it all here in one comment. It could fill a textbook. But to try to distill it down to its essence, we have a Congressional system that is designed to select office holders who are really good at politics, but don't know a damn thing about policy except as to pursue politics. The result is that no Congressman will take a policy position that means saying "no" to his electorate, even though they need to hear it, because that will cost him his job. Thus, Congressmen do NOTHING but spend money while in office in order to keep office, and we have a breakdown of policy.
Because they do not pursue policy, they do not act by making law. The executive and the judiciary are acting to fill the vacuum. The executive, as in the current case of United States v. Texas, has acted to confer legal status on 4.3 million illegal aliens with the justification "I have acted because Congress has not acted." However, inherent in that statement is the full meaning which is not stated: "I have acted because Congress has not acted the way I want them to."
The Courts have also acted to fill the void, as in the case of Massachussetts v. EPA where the Court gave standing to the state of Massachussetts to sue the federal government to regulate Carbon Dioxide emissions into the atmosphere as a pollutant. In so doing, not only did the Court make law, by declaring that the EPA had to regulate, they went much farther in making policy. That policy was to make "global warming/climate change" the official enforceable policy of the United States government.
When you make law, you inherently make a policy judgement that supports the law. That is supposed to be the exclusive domain of Congress, as the making of policy is dependent upon the political expression of the people, not arbitrarily imposed by Courts. And, because of the doctrine of Judicial Supremacy, which is an extension of Judicial Review, the Courts are the final arbiter of Constitutionality and the law. Having made policy by judicial fiat, it is no longer subject to the political process.
So I know it's long and rambling, but to get back to Trump, our dysfunctional political Congress, that lacks the will to properly make policy (or has deferred its policy making to the special interests that control them), has abdicated its constitutional function. The executive is, more than the Courts, filling that function. I fully expect the Supreme Court, by a 5-3 vote, to permit the Executive to do just that in United States v. Texas That is the structural situation of the executive office, and the question now is since we have an Imperial Presidency:
Who do we want to entrust with that power? For the sake of our country, it cannot be Hillary Clinton.
I fear we are in the midst of a national waking nightmare that will get a lot worse.