I think the only solution to this might be to embrace states rights. Half the country is conservative, half is liberal. It will never be unified or healed. You're better off going your separate ways and make 50 individual countries where you can have pockets of liberal and conservative strongholds. And then, we shall see who will do well in the global landscape.
Conservatives are never going to learn from their bad policies, because the entire country is always paying for their mistake. No wonder they still believe in trickle down economics. Rich states like New York and California are always paying for their stupidity. Your tax dollars go to spread that hate and ignorance.
These people are NEVER going to change their tune until THEY have to clean up their own mess. That's the only way they'll learn. What's the point of winning the white house in 3 years, when the republicans will obstruct everything you do? The pendulum keeps swining back and forth, and there are just too many ignorant conservative people. You cannot win. Even if you win, you lose. The right wing in America are not conservative, many of them are extremist.
If states like Oregon, Washington, Cali, New York and others decide embrace state rights, they have a much better chance at banning all firearms, full stop in their states.
I'm not saying that you should stop being a United States with your own currency, presidency and identity, but it's clear that the democratic process is being destroyed by political lobbying and corruption. You're too many people, and your states are too culturally different to have everything fit under one banner. What works in Oregon might not work in Alabama. Self governance becomes a much better idea when your country are actively destroying each other. Nobody can get anything done, and what gets done, gets destroyed by the other side, out of spite.
The European Union doesn't hold the answer as it has the opposite problem. But the other members can learn from the UKs stupidity and not have to pay for their stupidity. That's the key difference. You're not going to learn anything if you don't feel the blunt force of your actions.
If you have free mobility of people, you'd hope that all progressives would flock to progressive states, and maybe even flip some. Let's see a texas with 0% income tax, and a California with 40%. Let them battle it out, and we'll see which states will yield the most economic revenue and well being for people. I have a feeling the conservative strongholds will fall on such hard times, that they will look at how good they have it in the liberal places and turn them. The best way to show your way is better is not talking about it, but actually being able to live it and prove it. So you can see the contrast between conservative states that are falling apart and liberal ones that are doing much better.