Trust Republicans to go too far. They take a good idea - such as the notion that the federal government should enforce immigration laws and states should be able to help - and then drive it into the fringes. Witness a Fox News interview in which Sen. Lindsey Graham, R-S.C., declared, "We should change our Constitution and say if you come here illegally, and you have a child, that child is automatically not a citizen."

Graham has supported a pathway to citizenship for illegal immigrants. He opposed the new Arizona immigration law. So why would he advocate repealing part of the 14th Amendment - which, by the way, exists because the Grand Old Party wanted to stop efforts to keep freed slaves from becoming citizens?

Graham's right about this much: Illegal immigrants have taken advantage of the law. The Dallas Morning News reported Sunday that 60,000 babies are born annually in Texas to illegal immigrants. Last year, these "anchor babies" accounted for 16 percent of the state's births.

But it's not clear how many illegal immigrants are coming here to have babies as opposed to having babies in America because they are here.

Then there's the recent Washington Post story about "birth tourism" and affluent expectant mothers paying offshore consultants a $14,750 fee to obtain tourism visas that allow them to give birth in the United States and win U.S. citizenship for their babies.

No one likes to see adults game the system. In June, pollster Scott Rasmussen found that 58 percent of voters say a child born to an illegal immigrant should not automatically become a citizen of the United States.

But there are better ways to deal with those abuses. Direct the State Department to deny visas to would-be birth tourists. Keep the heat on employers who knowingly hire illegal workers. The new Arizona immigration law is designed to achieve "attrition through enforcement." Deport more adults who, unlike children, knowingly break the law.

But some Republicans want to keep going. Rep. Lamar Smith, R-Texas, is arguing that the 14th Amendment does not and never did confer automatic birthright citizenship.

Section One states, "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside."

"There are two elements, birth and subject to the jurisdiction," Chapman University Law School Dean John C. Eastman told me. "For about 50 years, we've just assumed birth was all you needed." But a review of the original debates and early court cases demonstrates a recognition that parents had to "show allegiance." If they broke federal law, they "never qualified" as being under U.S. jurisdiction.

This is where the argument gets dicey. Eastman has argued that a child born to a Saudi in the United States on a temporary student visa was not under U.S. jurisdiction, as the father had not declared allegiance to America. Eastman's answer is to let people come here to study or work, but as something less than guests.

This path could turn a melting-pot nation into an empire of the native born and law-abiding foreign workers who never have a chance to belong. Think Old Europe. Think Saudi Arabia.

But don't think America.