[handrous]

I'd say the key problem is that our electoral system and the structure of our government are broken in a few very serious ways, most of which are nearly impossible to fix, in no small part because fixing most of them would require at least one of our two major political parties to be OK with voting themselves into a weaker position (since some of the most important problems cause there to be only two viable parties at a time and fixing them would weaken the position of both those parties), or else they'd require a constitutional amendment, which is even less likely.

Most of our other problems are a consequence of that.