Guest Blog by: Robert Chao Romero On April 25, the United States Supreme Court ruled on the constitutionality of Arizona’s controversial SB-1070 law. This mean-spirited anti-immigrant legislation allows state law enforcement officials to check the immigration status of individuals as part of a lawful arrest, stop, or detention if they have “reasonable suspicion” the individual is undocumented. It also permits the warrantless arrest of individuals that police believe have committed deportable offenses. From an objective legal perspective, this law should be struck down based upon clear U.S. Supreme Court precedent. According to the 1976 U.S. Supreme Court case of De Canas v. Bica, “[p]ower to regulate immigration is unquestionably exclusively a federal power.” This important case stands for a simple, and uncontested, legal principle: it is the job of the federal government to regulate immigration. States and local governments do not have this authority. Only the federal government can create laws and policies which determine who gets to stay in this country and who can be forced to leave. Only the federal government has the authority to check the immigration status of individuals and make decisions about visas, asylum, deportation, etc. With limited exception, states and local governments cross the line into unconstitutional territory every time they try to engage in these types of activities. One basic exception to this rule is that Immigration and Customs Enforcement (ICE) is allowed to enter into special agreements with local law enforcement agencies which authorize them to enforce immigration laws. According to these “287(g)” agreements, ICE provides basic training to local police and then delegates to them some of its authority to regulate immigration. Outside of these special agreements it is illegal for states and cities to engage in the regulation of immigration. This is the current state of immigration law and it is uncontested. It is really that simple. SB 1070 and its modified version, House Bill 2162, blatantly violate this clear Supreme Court precedent because they take the regulation of immigration out of the hands of the federal government and place it unconstitutionally in the hands of Arizona state authorities. These laws basically say, “we the state of Arizona, by our own prerogative, authorize all of our police officers to regulate immigration by checking peoples’ immigration status.” Again, this is not contested legal territory. Regulation of immigration is entirely a federal prerogative. My UCLA undergraduate students could tell you that. The United States Supreme Court had a clear choice to make on April 25: Will it follow its own clearly-established precedent and strike down SB-1070? Or, will it follow the path of conservative judicial activism by upholding the law?