Are anchor babies illegal?

George Will quotes professor Lino Graglia of the University of Texas law school:

Congress has heard testimony estimating that more than two-thirds of all births in Los Angeles public hospitals, and more than half of all births in that city, and nearly 10 percent of all births in the nation in recent years, have been to mothers who are here illegally. Graglia seems to establish that there is no constitutional impediment to Congress ending the granting of birthright citizenship to those whose presence here is "not only without the government's consent but in violation of its law."

The professor says the 14th amendment was misinterpreted.

My chosen presidential candidate, Bill Richardson, was an anchor baby, but I do agree the 14th has been misinterpreted.