The death of empires, especially republics, is multiculturalism. Ben Franklin warned that we had a Republic, if we could keep it. Republics are kept by people of the same culture; they are lost when the hands keeping it are not the same. Lincoln, ironically, is the one who said that "a house divided cannot stand". Multiculturalism has divided the house of every empire before ours, and now ours. That always leads to a collapse, just as it is now.
The Greeks and Romans were strongest when they were ruled only by native Greek and Roman citizens. A person could become a citizen by service to the Republic, but could not rule. Their children, if native born, could. There was not amalgamation, but assimilation. When this period for each passed, the republics and the empires decayed from within and fell because the commonality, the unity, was gone. No longer were people "Greek" or "Roman", but they were Gauls, or Phoenicians, etc., and no longer this either empire last.
The same thing happened to the British Empire. "Make the world England" requires assimilation. There were Brits, and British subjects; nothing else. When the differing cultures were allowed and even encouraged to remain separate, the empire weakened and fell.
The same thing happened to the Soviets. When they were all Soviets, they were strong. When they became Chechen, or Cossack, or Belarusian, they fell.
That is what has happened here. The first fatal mistake was the importation of Africans. From there, we kept them separate and did not integrate them fully and quickly; we allowed and encouraged them to become a victim class, and that's always a benefit to political powers against the empire and republic. Andrew Jackson was the first to violate the Constitution and defy unity by his abhorrent treatment of natives; instead of making them Americans, he made them enemies and victims. Lincoln undermined the concept of states rights to a catastrophic degree and created "big gov't", that forces all under it to conform, but allows and encourages differences to be formed between the people. Ironically, Lincoln's plan to deport all Africans back to Africa might have short-circuited much of the problems of multiculturalism that arose from that mistake, but that idea died with him. From there, we allowed the influx of socialists during the 20s-50s, and FDRs policies created the Nanny State; allowing people to live off another's earnings. Johnson and all the rest after him have only further aided and abetted the divisions within the nation; keeping the people divided to keep their own political power and destroying the republic.
The solution, or the result anyway? The answer that history gives us from all those former republics and empires that died due to the disease of multiculturalism is to break up into smaller nations. Humans are tribal; a tribe cannot be multicultural. Just as all the other empires eventually dissolved into smaller nations, each more aligned with their own cultural/tribal identity and have tried to keep true to it, so too might/should/will this one we call America - and from the same fatal disease of multiculturalism.
