Tell me if I'm completely off the mark, but I don't think that the vast majority of Americans do actually feel that strongly about defending Trump that they would enter a civil war. Remember, only what, 25% of the voting age population voted for him, and out of those, many probably just hated Hillary.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition