[psychphysic]

That was sort of my point.

The idea is that Europe is much more varied than the US. Yet the UK is a country seemingly made up of countries. So difference isn't enough?

And the US already has a system to allow quite different laws to be enacted.

[ElfinTrousers]

Ah, I misunderstood. The thing is, although I believe the US government is more decentralized than your typical European government, and you're right that the various states have very different laws, the Federal government is still extremely powerful, and Federal law covers every subject that you can think of. Since the spectrum of political opinion represented is so wide, this means that any decision the Federal government makes will upset a lot of people. There basically never is a compromise decision that everyone feels at least OK about.