“Show me your papers.” That demand by police and immigration officials may become more frequent in the future because of Texas Senate Bill 4. But just what constitutes “papers”?

Years ago I went with friends to a restaurant in Villa Acuña. I was dressed in levis and boots and had just acquired a new Stetson hat. When we arrived at the restaurant I turned my car over to the watchman in the parking lot, knowing that he would expect a tip when I retrieved it. I said very lit...