In April 1980, two candidates were leading the race for the Republican presidential nomination—Ronald Reagan, who went on to win the election, and George H.W. Bush, who became his vice president. They participated in a presidential forum that month in Houston, and the very first question from the border-state audience touched on the topic of illegal immigration. “Do you think the children of illegal aliens should be allowed to attend the Texas public schools free,” asked the questioner, “or do you think that their parents should pay for their education?” The problem of illegal immigration “has…