In this case, utopia comes about when Blue America secedes from Red America:
Two years later, President De Blasio, elected leader of the Democratic States of North America, and President Abbott of the Republic of America, stood together on the platform on the border at St. Louis to sign the Dissolution Pact. The countries split the national debt and apportioned federal assets, while agreeing to temporarily share the currency. They divided the military (along with all nuclear capabilities), but signed a mutual defense agreement. There would be free travel between and through the new nations. “We will remain good neighbors,” President De Blasio remarked, “Even if we are no longer brothers, sisters, or differently-gendered siblings.” President Abbott politely maintained a poker face.
Click the link to read the whole snarky thing. It's probably much cleaner than what would really happen - - ethnic/racial cleansing would probably occur in various areas - - but it's fun to speculate about.