Opponents of illegal immigration argue that one way to fight would be to deny citizenship to U.S.-born children of people who enter the country illegally. Many legal experts say the only way to end automatic citizenship would be to amend the Constitution, which could take years and probably would not be successful. But lawmakers could also try to end birthright citizenship through legislation. That, however, would almost certainly result in a prolonged battle in court, said Peter Spiro, a professor and citizenship scholar at Temple's Beasley School of Law. "If I were handicapping it," Spiro said, "I would be willing to bet some serious money on the court finding the (citizenship) rule to be a constitutional one."