City governments and state government are increasingly at odds over issues like immigration. The answer lies in states bidding some cities farewell.
Within the American context, decentralization should take the form of granting statehood to large cities.
There are at least two ways this could happen.
One option is to grant statehood to each individual core city. In this context, a city is a specific city (i.e., the City of Phoenix), and not the larger metropolitan area in which it is located (I.e., the Phoenix metropolitan area). This would allow these cities more freedom in enacting (or not enacting) laws in accordance with the populations values.
Politically, there is something for everyone in this plan. Left-leaning cities would be freed from more right-leaning state governments, and would no longer have to deal with suburban and rural members of a larger state legislature.
At the same time, an exit of city centers would shift the rump legislatures in a more conservative direction. In a scenario such as this, Texass effort to restrict localized sanctuary cities, for example, would cease to even be controversial.