Former Texas Congressman Beto O’Rourke pulled himself from the presidential campaign trail this week to focus on grieving with his native El Paso, in the days after a mass shooting took the lives of at least 22 people. The move sparked speculation that the 2018 Senate candidate, who raised an astonishing $80 million in his upstart campaign against Sen. Ted Cruz, is mulling another rumble in Texas, this time for the seat held by GOP Sen. John Cornyn in an already crowded Democratic primary.

But amid a raw and emotional week, O’Rourke dismissed questions about a potential Senate bid, telling reporters in El Paso Wednesday, "No part of me right now is thinking about politics, is thinking about any campaign or election. All of me is with and thinking about this community. And so I'm going to be here to be with my hometown, and to do anything I can to be helpful."

Regardless of O’Rourke’s decision about another Senate run -- for which the candidate filing deadline is in December -- the Democratic contenders already seeking to oust Cornyn in 2020 are picking up right where O’Rourke left off in 2018, fueled by the party’s nearly quarter-century-held hopes of turning Texas blue. The state has not elected a Democrat to statewide office since 1994, but O’Rourke received more votes than any Democrat has in the history of Texas.

"In 2018, Beto O’Rourke destabilized Texas politics in a positive way for the Democrats," said Cal Jillson, a political science professor at Southern Methodist University. "The environment around the Texas Senate race is going to be one of an increasingly competitive Democratic Party."

From MJ Hegar, a retired Air Force major and former candidate who lost in Texas’ 31st Congressional District race in 2018, to Amanda Edwards, an African-American millennial and Houston City Council member, to Royce West, an African-American political fixture in the state Senate, the seven-way primary features a diverse crowd in a year in which the Lone Star state is expected to be in play.

"[A primary] is an opportunity for other talents in the state to rise through the ranks," Leah Askarinam, an analyst at Inside Elections, which currently rates the race as likely Republican. "Instead of recycling, kind of tried-and-true, somebody like Beto O’Rourke, there's an opportunity to find people who might not be as well known on a statewide level or on a national level, who could be interesting additions to the party."

Chris Bell, a former Texas congressman and 2006 gubernatorial nominee; Michael Cooper, a pastor and 2018 candidate for lieutenant governor; Sema Hernandez, an activist with the Poor People's Campaign and the daughter of immigrants who also ran for Senate in 2018; and Adrian Ocegueda, who ran for governor in 2018, are also running in the growing contest.

Texas voters will cast their ballots in the primaries on Super Tuesday, slated for March 3 of next year.

The Democrats seeking to unseat a Texas Republican

In one of the most closely-watched races of last year’s midterm elections, O’Rourke traveled to all of Texas' 254 counties, including ones he said hadn’t seen a Democrat in years, before he was ultimately toppled by Cruz by only three percentage points. But O’Rourke carved out a path for Democrats, making significant inroads for the party both statewide and lower on the ballot.

"Texas is the biggest battleground state … In a race against John Cornyn, our Democratic candidates are already in a tossup," said Abhi Rahman, communications director for the Texas Democratic Party, reinforcing Democrats’ belief that the changing demographics within the state give them a competitive edge that could potentially transform the electoral map.

"We know that we have to do more to galvanize those populations of color that did not turn out [in 2018] -- people in those populations under the age of 35 that did not turn out to vote but registered," Edwards, who would be the first African-American woman to represent Texas in the U.S. Senate if elected, told ABC News in an interview Thursday.

"I happen to be a millennial. I am a representative of that population. But moreover, that is a central theme of my campaign," she said.

Hegar, another of the 2020 Senate candidates hoping to end Republicans' decades-long grip on the nation's second most-populous state, told ABC News on Friday that she is "confident" about winning the primary and the general election because "I am not a politician, I am a working mom and a combat vet."

Considered by Jillson to be a front-runner along with West, Hegar, who completed three tours in Afghanistan, said, "We need to elect more service leaders."

West, who was first sent to the Texas state Senate in 1992 from a district that includes parts of Dallas and the outer suburbs, said he has a long record of "getting things done" and "working across the aisle."

"I’m prepared for this moment," said West. "We need this leadership coming from the state of Texas, in the U.S. Senate, as opposed to following all the time ... Not only am I a fighter, but I win and I can win for Texas."

West, who says he has the support of 10 of the 12 state Senate Democrats and 47 of the 67 state House Democrats, also told ABC News Friday that he's twice spoken with O’Rourke about his decision to run, and the former congressman said it was not his intention to jump into the Senate race.

Learning from O'Rourke's narrow loss

At this early stage, these Senate hopefuls say they're learning from O’Rourke's 2018 run as they seek to cast the 2020 cycle as ripe for a Democrat.

"He’s the one they know. He’s the one we associate with trying to get better leadership in the Senate," Hegar said of the questions about O’Rourke switching races. "It’s not reflective, in my opinion, of people not wanting him to run for president. It's reflective of John Cornyn’s vulnerability, because if he wasn't vulnerable people wouldn't be paying attention, and it’s reflective of the energy that we're seeing when we're driving all over the state."

"What we learned last cycle was that if you are authentic, and you're a real person, and you connect with people, and you show them that you're fighting for the same thing … we can win this. And that people are hungry to elect somebody who they don't see as a politician," she added.

Edwards, seeking to mirror O’Rourke’s emphasis on inclusivity throughout her campaign, is focused on turning out those voting blocs that she says didn’t show up last Election Day.

"What we saw with regard to Beto's campaign is that he led a very … far-reaching campaign," she said. "I think that was a strength in terms of building across very geographic boundaries: rural, suburban, urban. He touched all of Texas."

"I will not replicate what Beto did. We will be going to rural, urban and suburban counties … We will be very inclusive," she said. "But as far as every county in the entire state, we may not be able to."

The Houston City councilwoman also insisted that it will be "critically important" to court voters in the middle, who she said might feel "disconnected" from divisive politics, and that it is incumbent on Democrats to "galvanize that base" better than they have in recent cycles.

"I'm the candidate who's uniquely positioned to do that, both in terms of building coalitions that galvanize the base, but then also pulling from the middle," she said.

Meanwhile, West is adamant that O’Rourke’s near-miss last year was not a fluke, but instead the most recent example of Texas turning a shade of blue.

"I've learned that people think that was a political aberration," West said. "I look at it as a somewhat of a trend of Texas becoming purple and then blue. I think this time it will become blue."

"People, I believe, will make certain that we do everything we can in order to regain the soul of this country, as opposed to continuing to see us being divided," he added.

Will Texas be a battleground?

The last Democratic senator from Texas served until 1993, but the changing demographics within the state -- including what FiveThirtyEight calls population growth "in and around the state’s cities," plus O’Rourke’s competitive showing in last year’s race -- suggest that Texas could be a key battleground in 2020.

The contest between O’Rourke and Cruz was the closest Texas has seen in recent decades, but Republicans still eked out a victory. And this cycle, President Donald Trump will be on the ballot.

Earlier this week, the president traveled to El Paso to offer condolences to victims of last week's mass shooting and to meet with local leaders and first responders.

Trump, who also stopped in Dayton, Ohio, to honor the victims of the shooting there, told reporters in El Paso: "The love and the respect for the office of the presidency… it was no different here … the enthusiasm, the love, the respect."

But while Trump insists that he saw "enthusiasm" during his trip, and continues to talk about his crowd size in comparison to O’Rourke’s after both held dueling rallies on the same day earlier this year, the political impact of Trumpism in Texas is facing another test.

"The Senate race is going to be the signature race," said Jillson, the political science professor. "Below that, [in] the presidential race, Trump has roiled the political waters all over the country, and in Texas, he has destabilized the traditional Republican majority in Texas. And in 2018, that cost Republicans two U.S. House seats, two Texas Senate seats, and 12 Texas House seats, as well as hundreds of local county races [and] city races."

Still, Cornyn, a three-term Senate veteran who secured Trump’s endorsement early, has already raised a formidable war chest and is setting up a steep uphill climb for Democrats.

"While the Democrat primary gets messier by the day, we’re growing our field operation and adding grassroots support," said John Jackson, Cornyn’s campaign manager. "And whichever liberal emerges out of the runoff will find out why Sen. Cornyn has never lost an election."

And Cornyn is not Ted Cruz.

Cornyn is "sort of widely liked but not passionately liked, with relatively few people who dislike him," Jillson said. "Cornyn is a known quantity, widely acceptable, although he doesn't generate great excitement. So someone to challenge him has to generate more excitement."

Democrats, in the meantime, have signaled they are planning to square off using their winning issue of 2018: health care.

"After nearly two decades in Washington doing Mitch McConnell’s bidding and voting to hand out tax breaks to corporate special interests, spike health care costs, and gut protections for Texans with pre-existing conditions," said Democratic Senatorial Campaign Committee spokesperson Stewart Boss, "Sen. Cornyn has every reason to be worried about losing his seat."