I think what we’ve been disregarding is the militarization of not only paramilitary / right wing groups but also our police forces in general. With the surpluses they’ve been given from our wars in Afghanistan / Iraq and the federal military overspending in general, those organizations have become only a step away from actual military forces. Additionally they’re hiring ex military members frequently and the right has been courting them as well. Some of those forces might be ones that parallel those that the confederate army was born out of. It would take some coaxing from the national Republican Party but we’ve already seen police forces and right wing paramilitary militia organizations being chummy with each other. These forces don’t need to “take over” any city’s because they already have the upper hand in many of them.
The fact that we’ve seen left wing groups fighting with cops as well as the militias should tell you that we’re probably not as far away from serious violence as you think. its going to be he said, she said with who really caused the conflict just as it has been with the civil war. What we do know is that there are festering divides in the country and they are starting to boil over because they’re not being adequately addressed on a national level. (Much like slavery, states rights, etc... so long ago) So far, things are getting worse, not better... and the current leadership of the Republican Party isn’t helping things by playing to their radical base. I don’t believe the Dems have done that so much with Biden / Harris or even the upper echelon senators.