BLUFFTON, S.C. (AP) -- Republican White House hopeful Rudy Giuliani said Friday he wouldn't try to change laws that make citizens of children born in the U.S. to illegal immigrants, noting that it's a matter determined by the Constitution. "That's a very delicate balance that's been arrived at, and I wouldn't change that," Giuliani said in response to a question while campaigning at Sun City Hilton Head, a sprawling retirement community down the South Carolina coast from Charleston.