How do you win an election?
Do like the 1% do, and make sure that you own the candidate that is the nominee of each major political party.
The strategy is named “divide and conquer” and has been a great tool in the strategic genius tool-bag for as long as there has been conquest. Closely related is the idea of “defeat in detail” in which you locate your enemy then orient a superior force on part of them, then another part, and then another, etc. – maintaining local superiority of numbers/forces by keeping them separate so they cannot act together. When dealing with populations instead of armies, the natural divisions are on ethnic/racial lines, then wealth versus poverty, and a vacuous appeal to national identity.
Trump gave a flailing, crude, master-class in “defeat in detail” during the run up to his nomination, in which he focused on and humiliated and crushed each of his opponents while getting the others to sort of stand milling around waiting to see what happened. Until there were none. Meanwhile, the two party system has never been anything but “divide and conquer.”
Lest I sound like a “conspiracy nut” don’t fear; I’m not. What we are seeing is an “emergent conspiracy”, a sort of co-evolution in which two easily suborned groups evolve to use the same tactics and methods against eachother, one day waking up to realize they are the same thing – and not caring.