https://en.wikipedia.org/wiki/Reformed_Christianity#Predestination

Stemming from the theology of John Calvin, Reformed theologians teach that sin so affects human nature that they are unable even to exercise faith in Christ by their own will. While people are said to retain free will, in that they willfully sin, they are unable not to sin because of the corruption of their nature due to original sin. Reformed Christians believe that God predestined some people to be saved and others were predestined to eternal damnation.

Basically saying that if you voted wrong you are eternally damned for it. That's how I parsed it at least.

In addition to @[email protected]'s explanation, Calvinists believed that you could tell you were going to be saved if you were blessed in this life. So if you started a business and made a lot of money, that's a sign you had God's favor. The inverse, of course, is that if you're poor it's because you're a hellbound sinner. To map that to politics, the conclusion is that if you can't afford eggs it's because you didn't vote for the right candidate and don't deserve anything.