Colorado down through the Rio Grande Valley (include Austin and South Texas), west through to up the coast, and then East towards Yellowstone.
You’re probably going to have to let go of parts of Oregon and Nevada go to the self sovereigns and let the libertarians have Nevada as long as we get all the water sources upstream.
The border can be them, the frackers, and ag subsidies. Let Trump build in wall from Waco to Aurora if he wants.