It may seem hard to believe in a country where Donald Trump has a shot at becoming president, but people make rational political decisions. Most of the time, at least.

When an affluent voter in a high tax bracket who owns a business and a nice house shows up and votes for a Republican, that is a rational decision. And when a lower-income voter who has little access to health care and pays rent to a landlord shows up to vote for a Democrat, that is also a rational decision.

And for most of the population in most of the country, this is still how votes for the two parties break down: more affluent voters pull the lever for Republicans and less affluent voters do so for Democrats.