Most of those cities will destroy themselves before that happens.
Something that preppers have been warning. Chaos within the population centers would be much easier to achieve, than a heavy barrage of nukes.
Simply take out utilities such as electricity, water, and food supplies, and the cities will destroy themselves. Our military would be in disarray, confused about how to best retaliate. It is anyones guess what would the future hold for us.
Then there's your scenario, where liberal policies make cities rot from within. Same outcome.