The thing that I notice about this chart of spending presidential races pegged to inflation is that the high spending races have all been particularly vicious:
That was true of 1964 with Goldwater challenging LBJ and especially the infamous assassination year, 1968. The last two elections of this century have all been ratcheting up the discord and this year with the Right taking on a black commie will no doubt take the cake. Some of the thanks for this goes to the Supreme Court which guaranteed that Bush would win in 2000 and then compounded their influence by granting Super Pac donors the freedom of anonymous political speech.