It looks like a national divorce will be very difficult to avoid. On one side is the political establishment who look like they stole an election and who seem determined to dominate and impoverish the working class. This attempt to dominate has been going on for decades, as American manufacturing has been off-shored and millions of illegal workers have flooded the labor market. This combination of cheaper foreign and domestic labor has fattened corporate bottom lines but it has hollowed out entire regions (c.f. the "Rust Belt").
The Biden Administration looks to be dialing this up to 11, perhaps because they fear the 2022 elections when redistricting will eliminate a bunch of Democratic House seats. Or maybe they think that after stealing an election they don't have to respect the traditions of unity and governing in the interests of all citizens. But the agenda is radical indeed, not just banning oil drilling on federal lands but preventing oil drilling at all in the country.
Doubling the price of gasoline is a massively regressive tax. Combined with the loss of millions of jobs, it's hard to see how those on the losing end would want to stay in a union with a party who they suspect did not legitimately win the election, and who they seeing as governing illegitimately. And so to the "What comes next" part of the question. What will come next will be very, very messy. You see, we're not divided along "Red State/Blue State" lines, we're really all mixed together.
This is a map of the 2020 election returns by county. The size of the circles represents the number of votes for Joe Biden (blue) or Donald Trump (red). What you see are very few states that are almost all one color or another. A few, yes, but not many. And so to the breakup scenarios.
The Slovenian Option
On June 25, 1991 the province of Slovenia seceded from Yugoslavia. The Yugoslav People's Army (JNA) invaded the province but were defeated in a shockingly short 10 day conflict. Slovenian police blocked key road junctions and blockaded JNA barracks. The JNA forces never were able to establish unit or territorial cohesion. You could see something similar playing out in, say, West Virginia. Even though it is only an hour or so from Washington D.C. most of the state is very rough terrain. Local sheriffs would likely be able to block passage to unfriendly forces. The Slovenian option is the cleanest option, but is also the most limited - a fairly cohesive population (almost all red, almost no blue) combined with difficult terrain make this unlikely for most of the country.
The Croatian Option
Fighting in Croatia actually started before fighting broke out in Slovenia, when Serbs opposed to Croatian independence pre-emptively seceded from the province of Croatia. Things escalated and by the summer of 1991 it was a full scale shooting war between the JNA and the Croatian forces. This was no 10 day war; fighting continued into 1995 and much (perhaps most) of the ethnic Serb population became refugees. We might be able to term this the "Texan Option", where multiple enclaves of Blue voters exist in a sea of Red voting neighbors.
The Sarajevo Option
The siege of Sarajevo lasted four years and destroyed much of that city. It was famous for attacks on the civilian population, and indeed thousands of civilians were killed in the conflict by artillery and snipers, among other horsemen of the Apocalypse. This is what Civil War would look like in Atlanta, Detroit, Pittsburg, and Denver. The ugliness here will be proportional to just how hard the Democrats push the working class red state populations - and right now it looks like they want to push pretty hard.
The Mixed Option
Nothing says that these options are mutually exclusive. Indeed, they would probably all be seen although in different locales. But looking at the map it's hard to see a stable Blue government outside of New England/Mid-Atlantic and Pacific Coast.
In Yugoslavia something like 150,000 dead and 4M refugees were the result, from a starting Yugoslav population of 24M. It's hard to extrapolate those losses into what we would see but it's hard to imagine that there would not be many millions - maybe tens of millions - of refugees and hundreds of thousands dead. That's quite a butcher's bill for today's Progressive Left who seemingly will not just leave half the country alone.
