Fifty-three years ago, when newly elected Dwight Eisenhower moved into the White House, America's southern frontier was as porous as a spaghetti sieve. As many as 3 million illegal migrants had walked and waded northward over a period of several years for jobs in California, Arizona, Texas, and points beyond. President Eisenhower cut off this illegal traffic. He did it quickly and decisively with only 1,075 United States Border Patrol agents – less than one-tenth of today's force. Years later, the late Herbert Brownell Jr., Eisenhower's first attorney general, said in an interview with this writer that the president had...