Efforts to close the border in Texas and California have pushed more illegal crossings to Arizona, creating high anxiety in the southern part of that state. After years of frustration, Arizona has enacted a tough new law that requires local police to detain anyone they suspect of being in the country illegally. The law won't go into effect until this summer, but it's already ignited political fireworks from Washington to Mexico City. Two presidents and countless other officials are for and against the measure, but nobody expects any action from Congress in an election year. Today court challenges are being announced based on civil rights and the federal supremacy clause of the Constitution. With more than 10 million undocumented workers in the US already and more on the way, questions are being raised that have no easy answers.