An estimated 12 million illegal immigrants live in the US. The federal government is virtually paralysed over how to react, with conservatives like Arpaio calling for the arrest and deportation of illegal immigrants and increased border enforcement. Obama, many Democrats and some Republicans call for a system that will allow most to gain legal status after paying a fine and learning English, but reform efforts in 2006 and 2007 withered under sustained rightwing opposition.
I read a LOT of news, but had to get this tidbit via Drudge. Legacy media is so far silent on the subject. Personally I don't think that the Sheriff needs the permission of the federal government to enforce laws, federal or not. I believe that they are required to enforce ALL laws and picking and choosing which ones can be enforced or not is a travesty.