Clarify for me what this ultimate goal is? Only thing that I can think of is Caesar's Pax Romana, which would be nothing more than long-term stability under a totalitarian, imperial, slave-driven government that cracks down on medicinal and scientific progress and innovation - thus stagnating the country until it falls or it's ideals are significantly amended.
NCR would overpopulate and lose states if they spread to far as well.
Their Ultimate Goal is to unify the U.S.