There isn't a part in the Constitution giving the Feds the power of control involving immigration. It has power to ?establish a uniform Rule of Naturalization' the Feds have tried to maintain that this means that they may police it as they see fit. But, they are supposed to protect the country from outside threats. President Obama feels & has stated that the borders are secure & that there is no eminent threat to the security to the southern borders. In a nutshell doing nothing, leaving the border states on their own. So states like Arizona have said you're not doing your job, so we'll have to take care of the problem ourselves.