While doing this in the US would help get rid of the overt hate speech and groups, it wouldn't remove the actual hate or will to do such actions. On top of that, it would go against everything our country has stood for since inception. You can't start deporting or arresting people on thoughts alone...I've thought of beating the **** out of my neighbor many times & have told many of my freinds what a complete cornholer he is, but I haven't been arrested for battery or incitement. You can deport based on intent, as in they find a well developed plot to do something (for instance if they found my spy vs spy secret plans to burn his house down while he's on vacation)...or arrest based on action, yes I know in that case it would be too late but that is the country we live in and it's better than the alternative - even if that alternative is not immediately apparent or imminent. btw, does anyone else find it amusing Europe and the UK in particular was vastly critical of our response to 9/11, yet when it strikes them (on a scale exponentially smaller, but still horrific) they go absolutely medieval on their asses - and start outlawing free speech? When the chickens come home to roost...
This is not meant to refute, but I do not recall the UK or EU criticizing our post-9/11 actions, only the invasion of Iraq (kind of hard to make the case against the UK on that one). Please fill me in if I missed something.