It's also odd considering today's political climate- the casual observer would assume that that period was one of content and deference to authority, which is the complete opposite of today.
We talk a big game but in the end it seems we're always too scared to switch captains in the middle of a ball game.
I also think that since the 90s we've been in a pretty stable realignment. It appears that during the best of times and the worst of times, both parties can count on a large bulk of states and electoral votes. We just don't see wild swings anymore. There are no more Reagans who can win Massachusetts and no more Carters who can win Mississippi.