Friends of the current president have recalled how they occasionally saw Mexican workers in his father’s oil fields, part of a steady trickle of new immigrants from the other side of the Southern border who also took jobs as ranch hands, maids and groundskeepers.

Image Luz Reyes, owner of Doña Anitas Mexican restaurant, at the table where George W. Bush ate most Friday evenings while he lived in Midland, Tex. Some Republicans boycotted her restaurant in 2006 for a position she took on immigration. Credit... Erin Trieb for The New York Times

Randall Roden, one of Mr. Bush’s close childhood friends, recalled an upbringing that included “being aware that there were people who were poor and hard-working, and just looking for better opportunity, and a chance to do just about anything.”

Joe O’Neill, another friend from the time who remains close with Mr. Bush to this day and who helped introduce Mr. Bush to the first lady, said of the newcomers, “They were hard-working and they were usually very close families — there was generally a father and a mother at home; you noticed it.”

Mr. Bush’s closest boyhood contact with anyone of Hispanic descent seems to have been in Houston, where the Bushes moved when George W. Bush was in middle school, two years before he went to boarding school at Andover in Massachusetts. His mother sought household help in the local paper, and answered an advertisement for a Mexican woman who was seeking sponsorship in return for housekeeping services. The woman, Paula Rendon, moved in and has stayed on with the Bush family for decades, following George H.W. and Barbara Bush to the White House and back home.

The current president has mentioned her only rarely, but he has described her as “a second mother.” Mr. Bush declined several interview requests. But in a brief e-mail exchange, Mr. Bush’s younger brother Jeb said of Ms. Rendon, “I adore her,” and added, “I got pretty good at Spanish thanks to her.” But, he said, he became fluent through his wife, Columba, with whom he has three children whom George H. W. Bush once famously, and affectionately, called “the little brown ones.”

The Son Returns

Mr. Bush returned to Midland in 1975 to find a much more Hispanic town than the one he left behind, because of an influx of Mexicans who went there to cash in on the 1970s oil boom just as Mr. Bush did.