well then consider the premise of red states allied with red counties in blue states.
the blue states would be placed in the position of denying their red counties the right to self determination via partition.
the red counties in blue states (BSRCs) would then hypothetically be capable of non violently withdrawing services from large blue state cities until the large blue state cities saw the light and would let the red counties partition off.
the BSRCs would then be free to join the red states that have already partitioned.
it would be up to the remaining blue states to form a mutual self defense treaty with the red states— fairly routine, if NATO is any example, and a formidable challenge to any invader considering the natural invasion barrier to the whole formed by the atlantic and pacific oceans.
imaginative, yes. but bad times violence avoidence calls for good imagination.
However, the state has more ways to bully the cities/counties than vice-versa. For example, state pensions and/or benefits could be denied to citizens in cities or counties that attempted to secede. This would create an internal enemy of all those citizens who feared the loss of income.
I know that California, by its very odd nature, is a bad example but:
A few years back a number of districts in Los Angeles wished to secede because they felt they were being denied a level of service owed to them due to the amount of tax revenue they generated for LA. These areas got poorer police protection, etc.
In order for them to secede they had to get a majority vote of all LA city voters. When these districts tried to do it on their own they always failed. However, one year three districts simultaneously petitioned to secede, including the San Fernando Valley with all of its residents.
However, the LA elites were clever and decided to provide top-level services in the months leading up to the election and the sheeple were fooled and not enough voted for secession.
A similar thing would happen at the state level. It's not just about sticks like the National Guard that the state would use, but also carrots that they would deny those who chose to secede.