This past weekend the centre of El Paso, Texas was taken over by a parade of giant skulls, a celebration of Dia de Los Muertos, the Mexican festival of the dead.

For Ted Cruz – Republican senator from the Lone Star State, and runner-up to Donald Trump in the 2016 presidential primary – it may prove an ill omen.

Mr Cruz, 47, is in mortal political danger. He could be by far the biggest Republican scalp as America goes to the polls for the midterm Congressional elections on Tuesday.

It is from El Paso that his potential Democratic nemesis, the Spanish-speaking former musician Beto O’Rourke, has unexpectedly emerged, buoyed by a wave of support from Hispanic and millennial voters.

In this dusty…