Arizona as the other states of the United States have immigration laws to keep those who would take away job for naturalized citizens. President Obama is an opponent of the Dream Act. Republicans being economically savvy are watchful on how much the Dream Act could take away from naturalized citizens.
The Arizona's illegal immigration law does more to take away the rights of Arizona's citizens than it does to deter immigration. Illegal immigrants are often desperate and are willing to do illegal things to try to give their family a better life. However, when you start to take away the rights of your own citizens, you have a problem.