Well, the first executive orders are now out.
Unsurprisingly, Trump has "claimed" that he can do whatever he wants.
How much can he do? It depends on who falls in line. That’s really the only thing that remains to be seen.
I still have some optimism that the various court battles to compel action will be too numerous for him to achieve everything he wants. However, in areas where he’s ordered certain actions to stop, or removed certain regulations, the consequences will likely outrun the courts for quite a while. These particular Republicans are motivated by opportunity and not so much fear, It’s passive aggression by the Republican wussies. All it requires is that they do nothing. Let Trump run rough shod over our traditional institutions. Let him do anything he wants, so history records the destruction as a Trump thing. The reconstruction will be a Republican thing.
Trump is testing the waters. Being Trump he will escalate until he finds a limit. Trump can only do what he wants if he has enough help doing so. We’re about to find out what that looks like.