The anti-17thers always conveniently ignore the fact that congressional districts and state legislature seats tend to be heavily gerrymandered and rigged to elect a certain type of legislator. Probably 60-70% of americans are effectively powerless in the outcome of their congressional races and state legislative races. I know I'm in that boat. Several times, a solid majority of the regions in my district have voted for a Republican to represent us in the state senate, only to see the district go Democrat as a whole because 1/3rd of the district is in within Chicago city limits, and that portion gives 95% of its votes to the RATS, thus disenfrancing the other 2/3rds of the district's residences. A small bloc of black voters in Chicago basically guarantees that my heavily suburban state senate district will elect nothing but white Democrats.
My current "representation" in the Illinois State is some worthless Mike Madigan sock puppet. He's so wedded to Madigan's agenda that even though he's a state senator, he won't even prioritize bills that originate from the senate or his own Democrat caucus, if his boss Madigan has some house bill they want to fast track.
Good point about gerrymanders. And judges are meddling in gerrymanders more and more. Dangerous.
Certain geometric shapes [such as concave] could be forbidden unless there is a waterway as an official barrier. Something along those lines.
Few terms are more clear than the mathematical kind.