The creature that eventually came out of the swamp called Congress is not sectoral. Nor is it proportional representation. Nor is it a true party list. No one as yet can tell, except that it must come from outer space since no similar electoral monster exists on this planet. To understand our elections, we have to stray away for a moment from the field of law to the field of political science and theory.
Democracy is about the people ruling themselves.
Very few states do this directly, the Swiss cantons obviously coming to mind. The rest, republics, invest representatives of the people with power over the common weal for a term. How we elect those representatives tells us about how faithful we are to democracy. There are several ways to attempt this. The problem with that system is that it does not represent those who voted for losing candidates.