Representative F. James Sensenbrenner Jr. has no tolerance for illegal immigrants, either in his political life or personal life. “My housekeeper in Wisconsin was born in Wisconsin,” says Mr. Sensenbrenner, the Republican congressman and chairman of the House Judiciary Committee. “My housekeeper here is a naturalized U.S. citizen from Nicaragua.” Mr. Sensenbrenner is so loath to risk dealing with illegal immigrants that when his Cadillacs need cleaning, he prefers do-it-yourself car washes that require tokens. “They don’t have Montezuma’s picture on the front of them,” Mr. Sensenbrenner says of the tokens. He is sitting in his Capitol Hill office dominated...