IMO America as it once was can potentially be preserved in pockets here and there but preserving the entire union and returning to the founding spirit of the country is impossible. I'm sorry to say but I don't think we'll ever be breaking bread with NY and California in the future unless we compromise our own values. Short of a complete miracle and the vast majority turning back to God in a sincere way I'm not sure it's realistic to expect that we can keep the country wholly intact. If you want to use the Romans as an analogue then look at how the empire split up into a bunch of different kingdoms/principalities.

Anything's possible if God wills it, but I'm not sure if God wills it here.