要想阻止外国人到美国混公民，只有修宪。
要减少老中来美国生崽，床铺也不是没有办法，比如他可以规定育龄妇女申请旅游签证时必须在领馆验孕，证明没有怀孕。怀孕者一概拒签。
The concept of birthright citizenship was upheld by the U.S. Supreme Court in 1898 in United States v. Wong Kim Ark when the court affirmed the citizenship of a man born on U.S. soil to parents who were Chinese nationals.