The United States of America is a culturally diverse, multi-racial, multi-language country with a wide range of history.

It is also big. I just did some homework: In sheer size you in Europe could fit

The United Kingdom
Ireland
Italy
France
Germany
Austria
Poland
Luxembourg
Iceland
Portugal
and Switzerland
inside our borders and still have almost 2 million square miles left over.

Now. Tell me that Europeans could quickly resolve any divisive, controversial issue as explosive (no pun intended) as gun ownership and regulation is in the US.