It's counterintuitive but the most divisive arrangement is when the same party controls both Congress and the presidency a situation encountered in eight of the past 10 years. With government unified under a single party the minority has the least possible incentive to cooperate with the majority.
When I left Europe in 1987 I did so with the thought that my relevance as a composition teacher would benefit from a certain cool distance to certain tendencies I had been observing for several years with increasing disquiet.