DALLAS — Rep. Marc Veasey, D-Texas, spent a precious recent recess afternoon downtown, taping a debate against a political neophyte for Univision.

A translator speaks over Veasey, telling the Spanish-speaking TV audience that he is a “demócrata fuerte” — a strong Democrat. His primary rival, technology licensing attorney Tom Sanchez, speaks Spanish with ease to the viewers from the network’s skyscraper studio.

The chaotic linguistic exercise illustrates why, one week before the Lone Star State primary on March 4, Veasey must take his re-election seriously. He cannot let his candidacy get lost in translation.

The demographics of the 33rd District are stacked against Veasey, a native of Fort Worth. The district, based mostly in Dallas, is heavily Hispanic. It stretches from the historic Fort Worth Stockyards across deep pockets of poverty on the city’s east side, to the Dallas suburbs and Oak Cliff, the southwest neighborhood where Lee Harvey Oswald was taken into custody.

“I’ve worked hard to represent the entire district,” he said of his first term, in an interview in his Dallas office. “The only way any candidate, including myself, will be successful in this district is if you represent this entire district.”

The strategy to oust Veasey is clear, if not obvious. If another Democrat can mobilize enough Dallas and Hispanic voters, his re-election is in peril. And Sanchez has bet about a million dollars of his own cash that he can do it. Although polling is scarce, Veasey remains the tentative primary front-runner, and the nominee will almost certainly come to Congress in this heavily Democratic district.

Veasey has survived well-funded opposition before. His former foe, ex-state Rep. Domingo Garcia, spent more than $2 million in the Democratic primary and runoff in 2012. Garcia, a longtime Dallas politician, had far better name identification than Sanchez.

But that race also had a sharply different tone. Garcia stoked the regional rivalry between Dallas and Fort Worth. This time around, Sanchez is playing up his Fort Worth connections. A resident of Irving, a Dallas suburb, Sanchez has a campaign office in the Fort Worth Stockyards, a Hispanic side of town that includes the world’s largest honky-tonk, cowboys and a daily cattle drive for the benefit of tourists. In an interview, Sanchez joked about his “thousand cousins” in Cowtown.

Veasey’s political strength lies in his organization. His east Fort Worth base is made up of politically engaged African-Americans who boosted him to victory in 2012.

Veasey grew up in an African-American neighborhood on the west side and is a known commodity among that side of town’s local Chamber of Commerce-type political elites. Those residents, long tired of Dallas’ shadow, value this House seat as their own. The congressman’s fundraising reports are loaded with donors from those wealthy Fort Worth ZIP codes outside the district.

Beyond geography, Veasey rose in Fort Worth Democratic circles that had minimal opportunity to flex any political muscle in Congress since former Rep. Martin Frost, D-Texas, lost in 2004. A former Frost staffer, he wields the endorsement of state Sen. Wendy Davis and shares an adviser, J.D. Angle, with her. In fact, it was Davis’ campaign spokeswoman, Rebecca Acuna, who made the 40-minute trek from Fort Worth to Dallas to translate for him at the Univision debate.

But Sanchez’s spending unnerves some Veasey allies, especially in the expensive Dallas-Fort Worth television market. Sanchez, a former Marine, earned his fortune working for cellphone companies such as BlackBerry.

He gave about $1 million of that money recently to his campaign, which is now airing television advertisements on broadcast stations.

“It’s our turn,” Sanchez says into the camera in a spot that aired during the local evening news. “It’s our time. Ahora.”

There is also a Spanish version of the positive, biographical ad.

“You’ve got to take anyone seriously who goes up on network television,” said Matt Angle, a Democratic consultant and Veasey ally. “While I expect [Veasey] to win, he was smart to take any challenge seriously.”

As of the latest reporting period, Veasey had about $460,000 in the bank.

The incumbent was up with his own ad last week on cable, attacking Sanchez as a “Republican.”

Sanchez does have a history of donating to Republican candidates. As recently as the 2012 cycle, he donated to the presidential campaigns of Newt Gingrich, Mitt Romney and Texas Gov. Rick Perry. His donor history includes contributions to federal Democratic candidates, too.

“I’ve been approached by Republicans before. And the answer after 2012 was, they went insane,” Sanchez said in an interview of his former contacts with the GOP. “The Republicans went insane. … It’s a party that’s going to kill itself.”

Sanchez noted that while he contributed to Republicans in 2012, he eventually voted for President Barack Obama.

Sanchez is running to the left of Veasey on immigration and blames the congressman for the federal government’s deportations.

Veasey fired back, calling the charge “some kind of Republican trickery to confuse voters” in his interview with CQ Roll Call. He then pointed to endorsements from several high-profile Hispanic Democrats in the House. Rep. Luis V. Gutiérrez, D-Ill., recorded automated calls on Veasey’s behalf.

Veasey also boasts backing of the highest-ranking Hispanic lawmaker in the House, Rep. Xavier Becerra of California, along with his fellow Texas Democrats, Reps. Joaquin Castro and Pete Gallego. Both Castro and Gallego are former colleagues in the legislature.

The primary will most likely be decisive for Sanchez and Veasey in this heavily Democratic district. The winner needs 50 percent to avoid a runoff, which is likely because no other Democrat on the ballot boasts any serious money or campaign organization.

If Veasey prevails, he’ll have to continue to watch his back — at least until the next congressional redraw in Texas.

“Everybody should always consider themselves at risk,” Veasey said. “There’s no guarantee that anybody will ever come back.”