In Texas, one of the most scrutinized Senate races of the U.S. midterms has come down to that age-old election day axiom: Turnout.

Arguably the country's highest-profile midterm contest, it sets Republican Ted Cruz against upstart Democrat Beto O'Rourke. The race has captured headlines throughout the U.S. for months.

Cruz is a fierce Conservative and an old-school Texan (born in Calgary but raised in Houston), who challenged Trump for the Republican presidential nomination two years ago.

O'Rourke is pretty much the antithesis of Cruz. He opposes a border wall, wants tougher gun laws, promotes universal health care, and is that rarest of rare entities in Texas: A Democrat who might actually win.

Cruz is ahead in the polls, but O'Rourke is keeping it close and a win isn't beyond the realm of possibility.

WATCH Paul Hunter's feature from The National, 'Battleground Texas':

It’s one of the highest profile midterm races in America. Incumbent Ted Cruz is up against rising Democratic star Beto O’Rourke in a battle that's seen as key to the Democrats’ long-shot hopes of regaining the Senate. Our Paul Hunter goes down to the Lone Star State to check in on the race, the stakes and the possibilities. 12:54

Changing politics

Like so much of the country, Texas finds itself at a kind of cultural and political crossroads these days. Many in the state's old guard fret over increasingly fast-paced social changes driven by an ever-younger, more culturally diverse crowd.

In short, Texas is changing and so too are its politics. Think Stetsons versus skateboards.

And in a state that typically ranks at or near the bottom when it comes to voter turnout, both parties are desperately trying to persuade voters to actually get out and cast ballots come Nov. 6.

But in the Cruz vs. O'Rourke battle, it's a name not on the ballot that will likely drive the most votes: Donald Trump.

Increasingly, long-dormant Democrats have come out of the closet because of their frustration with his administration.

"We have to do something to stop Donald Trump," said Dana Rushing, Democratic Party chair in the staunchly Republican countryside of Llano county outside Austin.

Beto O'Rourke speaks during a campaign rally in Plano, Texas, on Sept. 15. (Laura Buckman/AFP/Getty Images)

Rushing grew up in Texas, but lived in Florida and then the U.S. northwest. She says she moved back home to find a changed Texas — more conservative and less tolerant than what she remembered.

Then came Trump's win in 2016, and Rushing was convinced she had to "get political." She and her friends now spend their days identifying likely Democratic voters and urging them to get out and vote against Trump.

Unseating Cruz, she says, is the only way right now to curtail the president.

"History is not going to be kind to Donald Trump," she says, predicting that if she does nothing to oppose Trump, she'll one day face the wrath of her granddaughter who'll demand to know why Rushing failed to act.

So she'll vote for O'Rourke. And Rushing is far from alone.

O'Rourke talks to Llano county Democratic Party chair Dana Rushing before a town hall meeting on Aug. 16 in Horseshoe Bay, Texas. (Chris Covatta/Getty Images)

In Dallas, others are working on how to get out the vote for O'Rourke among Hispanic Americans.

Typically reticent to actually turn out on election day, this demographic is seen as a key constituency for O'Rourke if he's to defeat Cruz.

Raphael Zamora, an American-born son of Mexican immigrants, spends much of his spare time these days knocking on doors in the Spanish-speaking neighbourhoods of Dallas.

His message at every doorstep: "If you're a young Latino, get out and vote because your vote really counts."

For Zamora, the midterms will be the first time he's ever voted.

His ballot will be marked for O'Rourke.

"I think [Trump] is racist," he says. "He is our president, so I do respect him, but I do not agree with his political views or his moral values."

Raphael Zamora, an American-born son of Mexican immigrants, has been spending a lot of time knocking on doors in the Spanish-speaking neighbourhoods of Dallas to encourage residents to vote in the U.S. midterms. (Jason Burles/CBC)

O'Rourke will take all the votes others can muster, but he himself needs little help firing up crowds.

At a campaign rally in Dallas last weekend, where most supporters wore trendy 'Beto' T-shirts that sell so quickly that distributors can no longer keep them in stock, organizers talk of a kind of Beto-mania.

When he takes the stage, O'Rourke emphasizes that turnout is key.

"I know we are up to the challenge," he said. "I know we are a match for this moment. I can feel it from you."

'This is Texas'

And yet, for all the anti-Trump sentiment, as Ted Cruz himself put it at a rally in Fort Worth the day before O'Rourke's: "This is Texas. And in Texas there are a whole lot more Conservatives than there are Liberals."

In the crowd that day, a Cruz supporter with a T-shirt reading "Texas: Beto Off Without Him" underlined Cruz's point for CBC News. "We want to keep Texas the way Texas was meant to be," he said. "Conservative."

Ted Cruz speaks at a rally in Forth Worth, Texas, on Oct. 19. (Jason Burles/CBC)

And as for Donald Trump, he added: "The man has brought our country into prosperity. The record numbers are everywhere. The facts are out there. It's just simple math."

Indeed, attitudes about Trump cut both ways.

Three nights later, inside a packed sports arena in Houston, Cruz wore a Texas-sized smile.

"God bless Donald Trump," he said, as the crowd chanted the president's name.

Trump soon joined Cruz onstage and made his pitch to get Republicans out to the polls.

Back in 2016, then-candidate Trump derided Cruz as "Lyin' Ted," but at the rally in Houston he told Cruz's fellow Texans their Senator has been a big help in helping Trump fulfill his agenda.

Donald Trump addresses the crowd at a packed Ted Cruz rally in Houston, Texas, on Oct. 22. (Jason Burles/CBC)

And he took shots at Beto O'Rourke.

"Ted's opponent is a stone cold phony," said Trump. "He pretends to be a moderate, but actually he's a radical, open-borders left-winger."

And the crowd, with their red Make America Great Again ball-caps, "Finish The Wall" placards and 'Trump 2020' T-shirts, roared.

As Trump left the arena, a woman in a bright blue cowboy hat pointed toward the presidential podium still onstage.

"Trump asked me to vote, so I just registered," she told CBC News. "I'm 53 years old and I never voted before in my life, and now I'm going to vote — Trump-Cruz all the way."

Another woman who'd been sitting in the front row during Trump's appearance, wearing a T-shirt that read "Adorable Deplorable," said she could now hardly wait to cast her ballot.

"[He's] just what we needed," she said, "to get all pumped up for this election."