I disagree, they are not irreconcilable. As Americans, we really do share more in common than what divides us.
What is dividing us currently are the political extremes - left and right - whose arguments, as julio stated, always stand on fundamentalist or black/white views of the world. Most of the civil war or sucession narrative comes from these extremes and they are growing. That is what we need to defend against. I definitely do not want to live in a communist country, but I do not want to live in a fascist one either. They are the two sides of the same coin - both are based on unfettered state power centered around one political party, usually one leader and aided by aligned corporate & academic interests.
Biden's victory shows that getting back to the middle and working to serve the majority of the population equally is the right and a popular approach.
Most of America is still in the middle like it was when Tocqueville wrote his famous book and do not believe in either extreme.
I'm a moderate independent voter in NH who is conservative fiscally, but liberal socially. When I talk to my neighbors or meet new people, we all tend to shake our heads at the state of our politics and the "culture wars". To most, it is considered frustrating, irresponsible and not helpful for our country. Everyone in my community knows who the local crackpots are on both sides, but they are still allowed their say in public or at the ballot box. The politicians who talk to both sides generally have more success, but expertise and local relevance (family history, work experience) continues to matter.
Trump lost twice here and, even though the Republicans have the legislature and governorship here, generally they are held in check from doing anything too wacky. They almost passed a anti-CRT bill, almost got more pro-gun laws through and did restrict the governor from ordering a lockdown, but overall NH is doing well with a federal representation of Democrats and a state representation of Republicans.
The one thing that has made people angry is our governor, Sununu (yes, the son of that Sununu who worked in the first Bush admin and was also governor of NH) and the Republican legislature reimbursed all the businesses who had been fined for COVID-19 violations. It could not be passed on its own and so the Republicans added it to the larger budget bill. The governor claims since, he does not have a line item veto power, he had to sign it. However, there were several other measures he objected to ahead of time and the legislature left on the cutting room floor so obviously this was not objectionable enough to him.
These are the kind of acts that erode people's confidence in government - when we have our next emergency that demands universal compliance i.e. the next pandemic which will happen, why would any business pay any heed to their state government's mandates? They'll simply take the fines, go about their business and get it reimbursed later for nothing. Outrageous.