That terrible math problem can be overcome by simply combining them.
Still unworkable. I will use Texas as an example.
1) Congressional districts must all contain approximately the same number of people. At this time, it is about 711,000 people per district. That sets the limit on district size.
2) Look at the zip +4. That will tell you that the maximum number of addresses in a zip code cannot be more than 10,000 people. That sets the constraint on the upper limit for zip codes.
3) In Houston, you can obtain the max limit on zip codes quite easily.
4) In a rural area, say, west Texas, there would be fewer people per zip code, so more zip codes would have to be combined to make a district. Making zip codes out of a larger area is not a solution either, as that would mean that postal workers would not be able to deliver the mail there as efficiently as in Houston, but I am digressing at this point.
5) Therefore, you would combine about 71 zip codes to make a district in Houston, and more than 71 in west Texas.
6) The key here is 71, the absolute minum number of zip codes needed to create each district.
7) To get 71 zip codes in Houston, you can use a relatively small area.
8) To get the number of required zip codes to meet the 711,000 requirement for a district in west Texas, you would need to combine thousands of square miles of area.
9) Since so many zip codes comprise an area, whether urban or rural, they could still be gerrymandered quite easily, by cherry picking which zip codes to use when drawing a district, and even more easily in a large area, such as west Texas. True, gerrymandering would be made more difficult, but not that much more difficult. And, in an area such as west Texas, there would be almost no impact at all.
10) Therefore, what you are suggesting is not a workable solution to end gerrymandering, although it would help a little.
