I thought this was an interesting observation by Murray Rothbard:
"Twenty years ago I was an extreme right-wing Republican ... who believed,as one friend pungently put it, that 'Senator Taft had sold out to the socialists.' Today, I am most likely to be called an extreme leftist, since I favor immediate withdrawal from Vietnam, denounce U.S. imperialism, advocate Black Power and have just joined the new Peace and Freedom Party. And yet my basic political views have not changed a single iota in these two decades!"
"It is obvious that something is very wrong with the old labels, with the categories of 'left' and 'right,' and with the ways in which we customarily apply these categories to American political life. My personal odyssey is unimportant; the important point is that if I can move from 'extreme right' to 'extreme left' merely by standing in one place, drastic though unrecognized changes must have taken place throughout the American political spectrum over the last generation."