Politics is cyclical. I know this is not earth-shattering news, but every once in a while, I need to be reminded. You don’t get too excited. And you don’t get too low (if you can help it).

I remember when Reagan slew the Democratic party. They were never going to win again, the Democrats. Their party rested on three pillars: public-sector labor unions, Hollywood, and aggrieved minorities. And that was not enough to win elections. Then, the Democrats started to win (in the two Clinton victories). And people asked, “Will the GOP ever come back?”

Margaret Thatcher slew the Labour party. They were absolutely finished — a Marxist rump. Then Blair won three elections. And the question was, “Will the Conservatives ever win again?”

In 2008, the Republicans got shellacked. We were finished. A New York Times editor wrote a book called “The Death of Conservatism.” Two years later, in 2010, we did the shellacking. Conservatism looked pretty un-dead. In 2012, Obama won reelection. In 2014, another Republican shellacking . . .

“Politics is cyclical” is perhaps the most boring sentence there is. I’m afraid it’s probably true, though.

P.S. From 1988 to 1992, we Republicans said something over and over — so did others, actually: “The Republicans have won five out of the last six presidential elections.” I once heard a Democrat grouse, “They start it in 1968 because it sounds better.” For a couple years now, I have heard the same sort of thing from the Democrats. What did Yogi Berra say about déjà vu?