The general issue is that we have a democracy (of sorts) and there is no coherent party platform/philosophy/approach that could make a majority happy -- at leas

The general issue is that we have a democracy (of sorts) and there is no coherent party platform/philosophy/approach that could make a majority happy -- at least not for long. As a result, in order to win some elections (have some power) the major parties are formed out of coalitions of disparate groups that can manage to hold their noses and work together. The bigger and more diverse your coalition the more you win, but bigger more diverse coalitions are harder for any individual member or subgroup to actually like. This is the dynamic pushing parties to be the most objectionable they can get away with, while still actually winning. The winning move isn't to be liked, but to be disliked less than your opponent. I'll just note, this is a general issue in democracies, not just the two-party system in the US. In the US the coalition is formed before the election and in some other systems the governing coalition is formed after. You can sometimes get a semblance of a coherent political approach that can outright win elections. But it doesn't last.