I wonder if part of it is that "undecided" or "centrist" voters are often not actually the mythical middle-of-the-road types the NYT wants, but instead contain a bunch of extreme and deeply insane views that happen to cancel each other out on a left/right scale.

I’ve done a ton of canvassing and door-knocking for local elections, and there are many people in this world who simply do not map neatly onto the U.S. political spectrum once you get them talking. Not due to extremism, typically, but rather reactionary self-interest.