There isn't one. And the sooner we all come to terms with that, the better off we and posterity will be. The constitutional government of the United States failed long before January 20th, 2025. Chasing sunk costs on this scale as futile, even if the alternatives are terrifying.
In my opinion, the best, just, course forward is a Constitutional Convention that dissolves the United States Government and replaces it with nothing. Let the states and territories govern themselves as they choose, and work out needed compacts and agreements going forward.
Nay, we must reform and reclaim a just federal government. Letting states drive themselves will turn the country into extreme violence.
Who days that doesn't happen now? Seems like wishful thinking.
Citizens should be allowed to move freely between them.
May the best governance win.