The main difference is that EU allows countries to leave the union, US doesn't. If EU starts to become corrupt and expand its influence like USA did over their states then countries will just leave.
> If EU starts to become corrupt and expand its influence like USA did over their states then countries will just leave
That just happened with UK. And it might happen again with Poland and Hungary.
Eu is not a supers state but it tries to become one. And the peoples of Europe do not like how a bunch of beaurocrats and politicians who they didn't even vote, are trying to change the way they live their lives, tell them what to do and mess with each country's internal affairs.
>But for a long time the EU was moving towards ever closer integration.
Some time ago people have more faith in the EU. But since EU derailed, beaurocrats and politicians started pushing EU towards a progressive and leftist dystopia. And people don't like that.
They have their history, their culture, their way of life, their customs and they want to live how they used to, without being told by the others how to live their lives.
No one apart from the far left wants Europe to become a melting pot in which nations, ethnicities, languages, customs, cultures dissappear.