In 1848, the discovery of gold brought hordes of prospectors to California. In 1889, millions of acres of free land set off a rush of settlers into Oklahoma. Today, we are told, the chance to get U.S. citizenship for their unborn children is rapidly filling the country with illegal immigrants.

Critics see this as a malignant phenomenon that ought to be stopped. So Arizona State Sen. Russell Pearce, author of the new law directing police to check the immigration status of people they suspect of being here illegally, has another idea: denying citizenship privileges to anyone born in his state to undocumented parents.