(CNN) -- America is fighting a border war. With itself.
U.S. President Barack Obama and his attorneys last week won a major battle. A judge overturned portions of a controversial new law in the southern state of Arizona aimed at fighting illegal immigration.
"Arizonans are already very angry at the federal government," CNN Correspondent Jessica Yellin said. "I suspect this will only turn up the heat on that rage."
The law has set-off a national debate about the roughly 11 million foreigners who live in the U.S. without permission and what the country's 300 million lawful residents should do about them.
Arizona is the most popular route in for the "illegals." Washington has placed guards, fences, cameras and sensors in the desert along the border. Nonetheless, thousands of illegals from neighboring Mexico, further south in the Americas and even as far away as China, keep finding a way in.
"They're doing anything and everything they can to come across," said Thomas Rudd of the U.S. Border Patrol.
Arizona says Washington just isn't trying hard enough to stop them.
In frustration, it adopted a law directing its state and local police to question people about their immigration status during any routine interaction, if there is reason to be suspicious. Immigrants would be required to carry their papers at all times.
President Barack Obama called the law a "misguided" effort that will target minorities for police attention and infringe on the national government's constitutional authority over immigration.
The judge agreed to some extent and overturned several key provisions. But politically, the president has reason for concern. Arizona's law in more popular nationwide than he is.
Our CNN/Opinion Research Corporation pollsters found that 47 percent of the public approves of the job he's doing overall, but fully 55 percent support the law he is fighting.
Obama could have let Arizona have its way; no one expects the president to approve of every measure adopted in every U.S. state.
Instead he chose to challenge the law and has won. But there will be appeals. The court case is hardly over and the political battle has barely begun.