I've been told that the Republicans and Democrats "switched sides" with respect to conservatism and liberalism in American politics in the 1950s. I find this event somewhat difficult to conceptualize. What did it look like to the passive American observer? Was there a mass exodus of Republicans into the Democratic party and vice versa? Did the parties just decide to flip-flop their platforms overnight? Did one party scheme to "take over" the other in order to win more votes?

I can conceptualize small shifts over time, but I find it difficult to conceptualize a very large shift at the same time from both parties that basically reversed or traded their platforms. And I also don't understand how the average American would have responded to this. If something like this happened today, I imagine people would find it utterly absurd, to the point I can't even imagine it happening today. I'm trying to imagine someone like Bernie Sanders calling himself a Republican or deciding to build a wall across the southern border of the country, and I just can't grasp this.