Texas Democrats eye GOP Senate seat. But first they must survive a contentious primary.

M.J. Hegar and Royce West, the two Democrats tangling over the Senate nomination to take on the state's senior senator, John Cornyn, and finish what Beto O'Rourke almost achieved, are at sharp odds in the lead up to Tuesday's primary runoff election. But both agree on at least two of the race's fundamental aspects.

The first is obvious: Cornyn must go. The second: the contest is a measure of experience.

For Hegar, a decorated former major in the U.S. Air Force and the Air National Guard, the primary is about bringing her "set of experiences" to the fore "to be able to fight for regular working Texans" in her second attempt at political office.

"I believe we need people with the right experience representing us in D.C.," she told ABC News in an interview on Friday, before adding what appeared to be a veiled swipe at her runoff rival. "I think we had an overrepresentation of career politicians and attorneys and we need more combat veterans who understand the cost of war."

West, a state senator, came up, in part, in the Dallas projects before becoming a prosecutor and serving a nearly 30-year career as a state lawmaker. For him, the race is about "bringing America back together" from division and replacing someone who has been "complicit with Donald Trump" -- a dig at Cornyn.

"Look at my resume," he said of his experience in an interview. "Democrats are tired of being victims of history. ... We can make history by electing me as the next United States senator from the state of Texas. And not just because I'm African American, but because I've readied myself for this time in history to represent the Democratic Party in Washington."

But the similarities in their pitches end there.

An outsider versus a longtime state lawmaker

Differentiating the two is Hegar's bear-hugging embrace of her outsider status, and West elevating his decades in the state Senate as a Democrat in reliably red Texas. Both are putting it to the voters to decide what kind of candidate should be put forward at a moment when the country is confronting twin crises.

Hegar, who first ran in 2018 but lost to GOP Rep. John Carter in Texas' 31st Congressional District, bills herself as a fighter and a mother, particularly at this moment of crisis that she says largely preceded the coronavirus and nationwide upheaval over race.

"What hasn't changed is the fact that we have had systemic racism and a health care crisis in Texas," she said. "These aren't new because we've been fighting for these things for years. What's new is they are now mainstream ... what's changed is that we have been able to reach people who maybe before the pandemic didn't understand why it was in their best interest that their neighbor has health insurance."

"We need more people who worked in health care -- I worked five years of health care," she continued. "We need more working moms who understand the seriousness of being able to hand down our country and a world that our kids can thrive in."

West, an African American political fixture in the state, casts himself as an effective lawmaker who can "get things done" and as the candidate who will meet the moment of racial reckoning, not only by potentially becoming the first Black senator from Texas, but also because of his long record on criminal justice reform, health care and education.

"I'm not just talking about what needs to be done," he said. "I have demonstrated results being in the minority party in a Republican-dominated state."

"That comes from my background as a former prosecutor and serving on the criminal justice committee for about 10 years," West continued. "I had to bring people together across the aisles."

Hegar was favored to win the primary back in March, but landed in a runoff with West after failing to secure more than 50% of the vote. She finished in first with 22%, just ahead of West's 15%, and is still considered the front-runner, as the top fundraiser in the race, who has the backing of the national Democratic establishment.

The national figures within the party lining up behind Hegar range from the Democratic Senatorial Campaign Committee to the progressive faction, including Sen. Elizabeth Warren. She's also garnered support from former presidential contender Pete Buttigieg, Planned Parenthood, EMILY's List and Giffords, the gun control organization.

West, for his part, has racked up endorsements from some top allies of former Vice President Joe Biden, including House Majority Whip James Clyburn, a political kingmaker in South Carolina who helped boost Biden's campaign to the presidential nomination, and Rep. Cedric Richmond, D-La., a national co-chair of the presumptive Democratic nominee's campaign. He's also earned the endorsements of Rep. Joaquin Castro, D-Texas, Rep. Eddie Bernice Johnson, D-Texas, who he called his mentor, five former Senate primary opponents and a majority of Democrats in the state legislature.

In their efforts to replicate the enthusiasm that carried O'Rourke's upstart bid just two years ago, the race has turned contentious in the closing stretch, with the two sparring over their credentials with attacks that have turned personal.

Battle for the nomination turns testy

In the last week, Hegar insinuated that comments from West could be linked to sexism, according to the Dallas Morning News, while West's campaign charged that Hegar made a "racially-tinged" jab against him.

Throughout the primary, West has frequently called himself a "true Democrat" -- an apparent slight against Hegar, who donated $10 to Cornyn in 2011, through VoteSane, a political action committee, and voted in the Republican primary in 2016.

She has said that she only made the donation after being told she must be a donor to get a meeting with an elected official, and that she voted in the Republican primary four years ago as an act of protest against Donald Trump.

West is adamant that "the voters will see ... that I am a true Democrat who has supported Democrats. I've been faithful to the Democratic Party."

His allies have also targeted Hegar, who received the endorsement from Senate Democrats' campaign arm in December 2019, and Democrats back in Washington, for intervening in the race -- and seeking to "cheat" West out of a shot at defeating Cornyn and becoming the first African American to represent Texas in the Senate.

"I know who I am, and I know that I am a Democrat," Hegar told ABC News in response to the strikes against her. "It hasn't really invaded my mental space at all or distracted me from the mission of beating John Cornyn ... People in Texas have a very sensitive bull---- meter."

But the growing hostility in the primary concerns Democrats in the state, who see the friendly fire as potentially hurting the eventual nominee in the long run.

"They're attacking each other," a Democratic strategist familiar with the race told ABC News. "They're giving Cornyn fodder and Cornyn has, I think, $20 million in the bank. It's a staggering amount so he's going to have a lot of room to be able to attack whoever comes out of this."

Cornyn's campaign has already seized on the party infighting, intervening in the race by running ads that tie West to some leaders of the progressive wing of the party, such as Sen. Bernie Sanders and Warren -- perhaps in an attempt to spur support for the longtime lawmaker among the party's more liberal voters.

Tuesday's race might also be reminiscent of Kentucky's Democratic Senate primary just last month, although the ideological parallels are not there since both Hegar and West are making a more moderate tact. Amy McGrath, a Marine fighter pilot who was backed by the DSCC, eked out a victory over progressive challenger Charles Booker, the youngest Black state lawmaker in the commonwealth. Booker ran a competitive campaign in the closing weeks as the energy from the nationwide unrest over racial injustice created a boon for his bid. But since his loss, he has yet to endorse McGrath in her challenge against Senate Majority Leader Mitch McConnell.

In Texas, both candidates signaled in interviews a willingness to be brought to the table, without explicitly saying they would outright endorse the other.

"I absolutely am going to do everything that it takes," Hegar said when asked if she would endorse West if he wins the runoff. "I will never stop supporting people who are going to move the needle on our values."

"We would have to sit down and have a discussion about where we are, and what issues I think are important," West said of endorsing Hegar if she wins. "And once we come to an agreement on that, I'd be more than happy to, and hopefully she'll do the same for me."

After Tuesday, a virtual unity tour is set to take place and is expected to feature both candidates, with details to be announced the day after the runoff election, according to Abhi Rahman, a spokesperson for the Texas Democratic Party.

Still, the competitiveness of the Democratic race reflects the urgency within the party to put the state in play -- fueled by a quarter-century-held hope of turning Texas blue.

Turning the Lone Star State blue

It's been nearly two years since O'Rourke's nearly successful Senate campaign against GOP Sen. Ted Cruz in a state that has not elected a Democrat to statewide office since 1994.

O'Rourke received more votes than any Democrat has in the history of Texas. He also carved out a path for the party, making significant inroads both statewide and lower on the ballot after traveling to all of Texas' 254 counties, including ones he said hadn't seen a Democrat in years. This year, in an election transformed by the coronavirus, the ability of either West or Hegar to reach untapped voters remains uncertain.

"In 2018, Beto O'Rourke struck a chord not only with Texas but this country. As a result of his campaign, we had numerous Democrats elected in the state House, on the judiciary, and we were two, maybe three, points away from winning the U.S. Senate race," West said.

Whomever earns the nomination, though, is still facing a tall order against Cornyn, a three-term Senate veteran who secured Trump's endorsement early. But the two Democrats in the closely watched primary are fiercely competing to pick up where O'Rourke left off.

"People talk about how unliked Ted Cruz is and how nobody likes him, when really the fact of the matter is, Ted Cruz had higher approvals than John Cornyn because people on the right love Ted Cruz, whereas, they're very lukewarm on John Cornyn," Rahman said.

This cycle, Trump is also on the ballot and Cornyn has spent most of the primary season tethering himself to the president, in the hopes of being buoyed by the the pro-Trump flank.

Despite the division, and the personal affronts, bringing both contenders together is ultimately the prospect of ousting Cornyn, who they view as out of touch with voters in the fast-changing battleground of Texas.

"Texas is ready to lead again," Hegar said. "We're tired of people like John Cornyn that are more D.C. than Texas. We're looking for leaders that are going to take on tough fights head-on and put the well-being of Texans first."

"The new Texas was not the same one that voted him in 20 years ago. It's more diverse and wants to see Texas values reflect their interests. Cornyn has not done that, and I will," West asserted, adding that he is ready to help Biden capture the state -- an ambitious feat not accomplished by a Democrat since 1976 when Jimmy Carter beat then-President Gerald Ford.