Cut off the areas that don't love the USA. Let the Leftys have their utopian strongholds, their own Constitution, their own set of laws. Require travel visas for their citizens to get out. They can call themselves the Delusional Disconnected States of Amerika.
Let them show us how great their ways are.
The rest of us can flourish.
The states are the political entities that entered into the pact known as the USA. Complicating things like you suggest would lead to needless war and bloodshed.