Just wanted to add this in as the debate is probably dead now but I see everyone with a view that's right and wrong but I wanted to say, it's almost impossible to get the total outcome of what good they would do comming in and what they would do if we kept them out. To really understand this we would have to continue going through trial and error.
Though personally it would be nice if they came in with the papers that would help with a lot of things I'm sure.