My study of similar charismatic leaders indicates that charismatic leaders like Donald J. Trump really do mean what they say. Since they are traditionally seeking to upset existing power structures, they cannot survive unless they take care of the followers who they ask to trust them and be willing to follow them despite high risks and potential social pressure. Unlike Obama, demonstrably Trump cannot lean on the support of a sympathetic press or the adoration of Hollywood. Instead, he has to rely on his relatively smaller base of working class voters in Wisconsin, Michigan and Pennsylvania to hold on to power. Given the narrowness of that band of political support, he really cannot afford to offend that base or back off his promises to them.
Indeed, one of the consistent patterns seen in charismatic leaders like Lincoln, Washington or Napoleon is that they were known for their commitment to strong principles of justice and fairness. If charismatic leaders were simply chaotic, insincere liars, then it would be difficult for them to attract die-hard followers. Their key inner core of supporters would abandon them if they lacked fidelity to their closely cherished beliefs. Followers maybe patient with their leaders, but they are not stupid about them. Like Napoleon and other leaders, you have seen and can count on Trump to say different things to different audiences to win their support. We can predict that he will occasionally offer alternative facts to get temporary advantages. In the long-run, however, it is a safe bet to assume that Donald Trump believes what he says and that he fully intends to make the sort of changes he promised during his campaign, particularly on the big picture issues like trade, immigration, and fighting ISIS.
The most important question is not whether Trump is sincere, but to what extent will he be able to do what he wants given the constraints of our U.S. Constitutional system.
The simple answer is no, as the highly charismatic Barack Obama learned. It is not so easy to get things done and make them stick because the U.S. Constitution created three separate branches of government and gave to each its own tools for protecting its turf, i.e. the famous checks and balances.
One of the best ways to improve your predictions of how much of their agenda any president will accomplish is to pay attention to the priorities of the legislative branch, Congress. In this regard, Trump does have an advantage in getting his policies put into law. His party controls both parts of the Congress, the House of Representatives and the U.S. Senate. Perhaps due to all the media attention focused on the president, one of the truisms of American government is that, the legislature has a lot more power than people think it does. After all, most of us do not pay much attention to how government really works and fail to follow how the actual details of a president's legislative agenda are hammered out in the House, the Senate and then the conference committees which combine their separate bills into one law that the president can then either sign or veto.
Unlike many U.S. governors, the president suffers from limits to his executive power because he does not have a line-item veto. Such a veto power would allow him to pick and choose which parts of a proposed law to accept or reject.
In view of these real world constraints, I think it is a wise bet to assume that President Trump will end up approving a lot of the existing, conservative, Republican policies that have been bottled up in the legislative branch under the Obama administration. This is because the quickest and safest way for Trump to get quality legislation completed quickly is to simply rubber stamp the legislative changes which have been consistently repressed and vetoed by Obama. If you know what the Republicans have been wanting to do in your particular field of interest, then it is a safe bet to assume they will get their way under President Trump.