But on a trip across southeast Texas on the eve of the primary, I met voters who — with an exception or two — did not seem to think they were near any abyss, as Mr. Cruz has warned. At a nostalgically 19th-century event — a rodeo parade on Saturday in Houston — Texans seemed perfectly at ease with the times. Trail riders by the thousands had converged on the downtown. They clopped through the skyscraper streets, in the shadow of what used to be the Enron towers, along with covered wagons and floats and marching bands. Not a politician was in sight.

Image The parade kicks off rodeo season in Houston. Credit... Michael Stravato for The New York Times

I watched for a while with Kemal Anbarci, a 52-year-old petroleum engineer, born in Turkey, who loves Houston. “I really feel American,” he said. “I feel like I belong here.” He said he voted Republican when he lived in California, but was waiting until after the primary to see who is the most unifying candidate. He called Houston “a wonderful place to be if you are not native-born.” He observed that the riders in the parade were ethnically diverse, but rode in segregated groups. “It’s wonderful,” he said, “but they are in chunks.” He laughed.

Some of the chunks reflect the Texas story. Mexican-Americans in sombreros, holding lariats and with their exquisitely trained and groomed dancing horses. Hundreds of members of the huge array of African-American riding clubs in Texas. Bo Lundford, on his quarter horse, Doc, was the “trail boss” for the Black History Riders of America, a group that honors the memory of the one-third of Texas cowboys who, Mr. Lundford said, were black or Hispanic. He was leaning toward Bernie Sanders and did not trust Mr. Trump with the nuclear button.