The ordinary American - as far as I can tell - knows so much less than he did fifty years ago and has such poor work habits compared with fifty years ago that the average multiplicand of knowledge/capabilities is a much smaller number than it was in 1961.
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.