Although the courts don’t address political questions under the separation of powers doctrine, they address redistricting because the composition of Congress itself is affected, reducing the public’s ability to use the ballot effectively to handle it ourselves (see also Enforcing Existing Access Protections). The separation of powers doctrine assumes the public freely elects Congress and state legislatures.
Economic level is a population demographic. The question of whether a state's United States districts reflect its economic levels can be resolved using printed matter: the census, other government information and the National District Map. The motives of the drafters need not be considered by the courts, just the composition of the state's districts. Even when it happens accidentally a distorted reflection must be corrected, a bright-line rule.
Image, Alex Borland