Politically this is the classic “rotten borough/pocket borough” problem in a nutshell though. People move away, and you are left with a seat controlled by a ridiculously small number of people who nevertheless control a constitutionally-allocated location.

In the UK this got down to some districts having literally single-resident or single-family districts. And it’s super easy to influence the residents when there’s a single master who controls the borough… kinda like coal in WV.

https://en.m.wikipedia.org/wiki/Rotten_and_pocket_boroughs