Hugo,
I read your article on Twitter. I think you have a grasp of the weak points in the US Constitution and the difficulty of fixing them. You understand the problems of governing 50 semi-independent countries. (For example, laws of Louisiana are still based on the Napoleonic Code. Others come from English Common Law. There might well be laws in New York based on the laws of the Netherlands. I don’t know.) These state laws are supposed to be subject to federal laws, but the bloodiest war that America ever fought was our civil war. It was fought over State’s Rights versus federal laws that did not allow individual states to withdraw from the United States.
Most people think that the war was fought to free the slaves but that was not the primary issue. While the anti-slavery people certainly fuelled the war fever, Abraham Lincoln hoped to entice the slave states to come back into the Union voluntarily, so he did not say anything about slavery until late in the war, after it was made clear that the army of the Rebel states was beaten. He passed the Emancipation Proclamation against stiff resistance from both sides.
Slavery was abolished, but in name only. We now call it racism and our current politicians play race politics.
After the war, African-Americans were free but they still had to work under harsh conditions to feed their families. It was not too much better than slavery.
In our time things have improved somewhat for African-Americans but we still see in this last election the blatant attempts to disenfranchise African-American voters. This is common in the former slave states but it can happen anywhere in the US.
If you are interested, I think the best book critiquing the US Constitution was Democracy in America written by a French national, Alexis de Tocqueville, in 1835.
The first and second volumes are available at Amazon Kindle, free. The original is in French but it has been translated to English and most European languages.
Kurt