Rob, the mistake you are making is assuming “constituents” is meant to mean people, or voters, or the whole population of the country. Not at all. Better to think of it as “special interest groups.” It is often said that Republicans are the party of the 1%, ie, of the rich.
(Bush speaking at a campaign dinner to a group of his wealthy donors; bold mine)
George W. Bush:
What an impressive crowd: the haves, and the have-mores. Some people call you the elite, I call you my base.
Democratic base is supposed to be workers and middle class, but it warped lately into “victims” in general (all kind of “victimized” minorities). If you are not a victim, or don’t feel like one, they’ll make sure you understand you are. That’s where the PC indoctrination and terror come into play.
Your view of politicians is utterly cynical. Yes, some enter the game for personal monetary gain. But that’s a side effect of how and why parties were formed. A group of people decide to defend their interests, get together, form a party and select some among themselves to represent them. That’s how even Magna Carta was born.