The problem of Gerrymandering has beset US politics for generations. Sophisticated computer programmes make it easier to accomplish. In the UK we prided ourselves on a non-partisan system for "re-districting", which involved work by the Boundary Commissions (from which active - and recently active - politicians were barred) which produced proposals which went out for public consultation - and allowed Local Inquiries held by an independent semi-judicial Inspector. The primary objective was to produce constituencies (the 'British' word for 'districts') which were geographically coherent and which kept communities together. Those things we were proudest of are being done away with by the current government.
So Gerrymandering is going to be a big issue in both the USA and UK.
A documentary has been produced in the USA which highlights the issues - it is currently being shown in some cinemas. There is a website which includes a trailer for the film - and background information. It is available here.