A second civil war in the United States would be divided along ideological lines, but there won't just be two of them. People will divide against one another, breaking into smaller "tribal" units based on affinity and common ideology. States will fracture away from the Federal government, which will be increasingly inept at holding back the ensuing chaos and attempting to establish control, provide services, etc., while at the same time the Fed will attempt to increase a greater hold over the people, to the point where something resembling "Martial law" is declared, possibly with a national pandemic as the justification. Nevertheless, the Feds won't be able to sustain the power grab, and the whole thing will collapse under its own, bloated weight. Most of the States will find themselves in a similar pickle, to the degree that they've bought into the idea of centralized control and regulation.
Given that there are more private gun owners in the United States than the five largest standing armies in the world combined, I would say no one is going to win this fight. Look for the dollar to lose any value as real currency, the government to become irrelevant, and most people to survive (those who do, anyway) on a barter system and via the black market. The survivors will be the winners. Whether or not anything rises from the ashes remains to be seen, but its dubious, at best. There is no longer a common vision for the common good, as existed in the Revolution and as understood even in the Civil War (competing visions for the common good). There's no longer even a common definition of "good." Therefore, it is doubtful we'll be able to remain a single people.
What happens when a Marine tries to spark a 2nd American Revolution by assassinating the next President on Inauguration Day? Read Jefferson's Road: The Spirit of Resistance
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The war begins in Jefferson's Road: Patriots and Tyrants
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Paperback: Coming this Fall