I consider that question in my latest Bloomberg column, and actually contrary to conventional wisdom the rationality of extreme presidential tweeting cannot be ruled out. Here is just one bit in a longer argument:
On top of all that, now imagine that you consider nationalism, resurrecting America as it once was, negotiating from strength, returning to older notions of masculinity and “building a wall” as the major issues of the day. You don’t see the traditional Republican concerns with cutting taxes and repealing Obamacare as all that salient for reversing America’s deterioration, even if you are willing to go along with those reforms. Nor, given your nationalism and unilateralism, do you see alienating allies as a major cost of opining so openly.
In that rather pessimistic view of the world, it might make sense to give up entirely on the idea that your administration will accomplish much in the way of policy, at least as the concept is traditionally understood. Instead, you might be thinking of shifting the window of policy debate over a 10- to 20-year period. That is, you might be hoping the American public will be thinking in more Trumpian terms a few administrations from now, even if outwardly they have rejected your legacy. It then will be the case that mainstream politicians will work to implement some Trumpian ideas through more traditional channels.
Do read the whole thing.