This is not Ted Cruz’s Texas. Neither is Mr. O’Rourke’s hometown (and mine) of El Paso. It’s a tattooed, blue-collar, Latino city of nearly one million. Mr. Cruz hardly comes here; his last visit he attracted just 2,000 people at a West Side high school — on a Saturday. This Texas hasn’t benefited from a quarter-century of unbroken Republican power. The biggest employer, the Army, ships people out just as quickly as it ships them in. A sprawling city of rail yards and refineries, El Paso has one of the highest illiteracy rates in America and some of its worst access to health care.

There’s a lot more of this Texas: the Lower Rio Grande Valley, San Antonio, South Dallas, East Austin and inside the Loop in Houston. This is a young Texas, about which there is a prevailing myth: It doesn’t vote. But that myth is being sorely tested. Some 15.6 million people are registered to vote this year, 1.6 million more than in 2014. More than four million have voted so far; so far in El Paso this year’s turnout has looked more like a presidential contest than a midterm.

There’s another myth about Texas: “Yeah, but it’s still Texas.” Which is to say, whatever the personalities and trends might indicate, in the end, Texas will vote as it always has, for crimson-red candidates.

As Erica Grieder at The Houston Chronicle has pointed out, that’s about the laziest thing that non-Texan experts on politics can say. The number of Texans who identify as conservative has flattened, according to the Texas Politics Project at the University of Texas at Austin, while the number who identify as progressive has swollen.

This election is an exercise in brute electoral force: the full on clash of the real, modern Texas with a worn out, calcified caricature. “This is not a persuasion election,” said James Henson, a University of Texas political scientist. “This is a mobilization election.”

The Cruz-O’Rourke race may be the main event, but the ballot is full of competitive matchups. Attorney General Ken Paxton, a Republican, may lose to a Houston lawyer named Justin Nelson. Agriculture Commissioner Sid Miller has his hands full with his Democratic opponent, a retired Air Force colonel named Kim Olson. Up in Dallas, Representative Pete Sessions, a Republican, is hearing the footsteps of the former N.F.L. player Colin Allred. In the western Houston suburbs, the Democrat, Lizzie Fletcher, is just a few points behind the incumbent, John Culberson. The Texas Tribune reports that Republicans may even lose their supermajority in the State Senate.

Another myth? Latinos don’t vote. In fact, Latino turnout in Texas has been creeping up, though it’s not yet at the same rate as Anglos. It’s a chicken-and-egg problem: Candidates spend so much time talking to Anglo voters they get around to Latinos late, so they’re less motivated.