@gleick An AI will have be trained on _something_, maybe your existing drunkards walk boundaries? I feel it might be very unfair indeed, and nobody could criticise it, because nobody would know how it works.
A branch of the public service can do this job very well. (Like the branch you currently have that handles pensions). It is a straightforward clerical job, done, as you say, according to simple rules..
In Australia, we call it the Australian Electoral Commission https://www.aec.gov.au/redistributions - they do boundaries for all electoral purposes all across the federation. It works just fine.
I feel the USA's Reaganite(?) 'less government is better' trope has led you to this place. It is an ideology, not a fact.