Two woman walk along the U.S.-Mexico border showing graffiti that reads "the walls" in Nogales, Sonora, Mexico, Tuesday, July 27, 2010. Arizona's new immigration law SB1070 takes effect Thursday, July 29. (AP Photo/Jae C. Hong)

Photo by: Jae C. Hong

Two woman walk along the U.S.-Mexico border showing graffiti that reads "the walls" in Nogales, Sonora, Mexico, Tuesday, July 27, 2010. Arizona's new immigration law SB1070 takes effect Thursday, July 29. (AP Photo/Jae C. Hong)