Up till now, I have treated Donald Trump as a generic Republican President who will sign off on the generic Republican legislative agenda. I have had two reasons for believing so. First Donald Trump doesn't know much about policy and doesn't much care, so he is bound to be someone's puppet. Congressional Republicans expect he will be theirs. The other reason is that, despite his crass behavior, Trump is basically a typical member of the Republican donor class, a businessman, and there is every reason to expect that he will share their general priorities of cutting taxes and gutting regulations, especially since he presumably expects his own businesses to benefit as a result.
But there are ways that Trump differs from a generic Republican. One difference is that he has genuine policy differences from them.
Most notably, he has appealed to the base in opposing immigration, while the donor class favors it. This is actually a less important difference that many people, especially members of the Republican base, think. The Republican base is convinced that the donor class wants to let in a lot of immigrants, legal and illegal, to keep wages low. While this is probably true, it does not appear to be anywhere near as high a priority for the donors as the base thinks. For the most part, the donors appear to have conceded this issue to the base and decided that the electoral price of enraging the base is not worth the economic advantage of lower wages. To the extent that the donor class continues to favor an opening to immigrants, it is mostly because they see Hispanic voters as the wave of the future and want to appeal to them. (I hope to write more on that later). But Republican donors have showing willingness to be anti-immigrant before, e.g., GWB's workplace raids. Although Trump is backing away from his more extreme promises, such as to build an impermeable wall and force Mexico to pay for it, and to deport 11 million people within 18 months, we may expect him to feel sufficiently bound to his promises and his base to launch some sort of crackdown, so long as it does not involve a burdensome regulation on business. The donor class may not be thrilled, but they will presumably acquiesce for the sake of their legislative agenda.
Next, Trump opposed international trade and businesses outsourcing operations overseas. In this he strongly disagrees with the donor class. How far he is prepared to go in renegotiating trade deals and slapping on protective tariffs remains a matter of speculation. One thing he has shown himself willing to do is use his powers of persuasion to talk to companies wanting to send operations overseas. Thus far he has apparently persuaded Ford not to shift production of Lincolns from a plant in Kentucky to Mexico (although the plant itself was not going to be shut down either way). He is apparently now working on persuading Carrier Air Conditioning not to close a plant in Indiana. And no doubt there will be other such instances. Unlike immigration, which the Republican donor class has already largely conceded, this one promises to provoke more resistance from the donor class. One libertarian-minded Republican has already protested, " We live in a constitutional republic, not an autocracy. Business-specific meddling shouldn't be normalized."
And then there is the matter of foreign policy. This is, of course, the area where the President has the greatest unilateral power and can most strongly impress his stamp. It is also an area which Trump knows nothing about and does not seem all that interested in learning. Thus far he has had only two intelligence briefings, although intelligence are offered daily and most Presidents-elect have had daily briefings, as has Vice-President Mike Pence. Thus far Trump's policy remains something of a mystery. He appears less eager for war than the bipartisan foreign policy consensus, but every bit as hostile to diplomacy as any generic Republican, despite his fondness for "deals." Presumably some of his nuttier pronouncements, such as a desire to "take the oil," the assurance that his best generals would come up with a plan to defeat ISIS in 30 days, and his speculations that why shouldn't we use nuclear weapons will fall away when confronted with the realities of power. He generally seems to favor a more pro-Russian policy than most Republicans, although it is anyone's guess how long that will last once we and Russia have our first disagreement (as is inevitable when nations have differing interests). Ultimately, Trump's views on foreign policy, and the extent to which he has any, remain a mystery to be learned in real time.
But not all Trump's differences from a generic Republican are matters of policy. Many are matters of personal style. More on that next.