At various times from various people I have heard expressed a folk theory of American politics that "these things go in cycles" and "politics is like a pendulum".
But is this true?
My investigation started with Arthur Schlesinger Jr.'s (that Jr. part is important) 1999 essay in The Cycles of American History that addressed my question quite directly, and laid out an account of cycles in American politics.
It turns out that the theory that American politics proceeds in cycles is an old idea, which I suppose makes sense for a folk theory. Ralph Waldo Emerson describes a cycle of reform in 1841 and Henry Adams (yes, one of those Adams's) described such a cycle writing in the 1890s. Adams saw 12 year cycles in American politics, alternating between centralization and diffusion. Arthur M. Schlesinger Sr. saw those cycles as 16 year cycles alternating between liberalism and conservatism, and counted 11 such cycles in 1949. Junior describes some other theories of cycles, and reasoning that this is driven in part by generational change, and leaning on the works of Jose Ortega y Gasset and Karl Mannhiem and his father, comes to an estimate of American political cycles that last about a generation - 30 years or so, up and down.
Now, all this is well and good; but when it comes to theories of history I always worry about painting a target around the arrow, overfitting to our limited data and small sample size. So my next question was: "has anybody actually tested this?" And surprise, surprise, this hypothesis jumped the fence and ended up in political science country, where, sure enough, my Googling revealed a paper testing Juniors's hypothesis - and finding it supported. Merill, Grofman, and Brunell analyze party vote share between 1854 and 2006 and clearly identify cyclical patterns. Reading a 2014 piece by Helmut Norpoth which briefly reviews the evidence for cycles in American politics, and reading all this it seems to me that the partisan cyclicality of American elections is fairly well established fact. Which in itself is probably sufficient to validate the folk theory and prove momma right.
But Emerson, Adams, both Schlesingers and all the other historical theorists are positing more than partisan cyclicality. They see an ideological cyclicality in American politics, with Americans not just swinging between Republicans and Democrats, but between left and right. The political science above can't speak to that, given how much the parties have shifted ideologically over that time.
In 1860 the Democrats were the party of treason in defense white supremacy, while in 2016 the Republicans now occupy that role. During Reconstruction, the Democrats were essentially the political wing of the Ku Klux Klan, while today, black Republicans are only slightly more common than unicorns.
So to answer the question of ideological cycles, I need other evidence. Enter James Stimson, who studies exactly this topic and has helpfully written a book addressing this very question. You'll have to make do with I could gather about its contents from a Google preview, since I was unwilling to buy it, too impatient to borrow it, and, despite valiant efforts, unable to pirate it.
But, dear reader, my gleanings were a treasure. Stimson looks at decades of polling on hundreds of issues and questions, trying to get at the underlying ideological mood of the American public, and sure enough his graphs show what looks a lot like an ideological cycle in American politcs, right around when the historical theorists and everyone else would think:
Stinson points out that his data suggest an interesting idea about these ideological cycles, which is that the public opinion change proceeds the political change, that e.g. Reagan was a symptom of a change more than a cause - which makes sense to me but does challenge a sudden-break theory of political change.
But I'd like to point out that all of this is only around 1 or 2 cycles worth of change, so while its suggestive evidence its hardly definitive proof of ideological cycles.
Still, all told, that folk theory looks pretty strong, and I'm fairly persuaded of it.
