” If there are food shortages, then these people will be in deep trouble.”
Therein lies the solution to the large red city problem.
Starve them.
Think they’ll just sit in their squlid apartment slums and just die? I see them in raiding parties into the breadbasket red areas where they’ll try and take everything not nailed down.
They won’t care about dying because that’s what they’re facing at home.
And reds are very scattered by demographics.
Better organize and store lots of ammo.