An insurgent candidate at odds with party elites attempts to seize the nomination from establishment rivals: That infighting roiling the Democratic presidential race is playing out in this week’s Super Tuesday congressional primaries.

Just as Sen. Bernie Sanders (I-Vt.) is rankling moderate Democrats in his quest for the presidency, two Texas House candidates — one a Democrat, the other a Republican — have crossed swords with party regulars in their bid to unseat veteran incumbents. The same dynamic exists in a pair of Democratic Senate primaries, in North Carolina and Texas.

All told, while Sanders’s performance might headline Super Tuesday’s results, the down-ballot races could say just as much about the present willingness of each party’s voters to eschew pragmatists and dealmakers for more ideologically driven candidates.

No race is being more closely watched on Capitol Hill than the Democratic primary in Texas’s 28th Congressional District, where Rep. Henry Cuellar is seeking nomination to a ninth term representing a heavily Latino swath stretching from the Rio Grande to the San Antonio suburbs.

Cuellar is one of the most conservative members of the House Democratic Caucus; he once backed Republican George W. Bush’s presidential bid and has more recently stumped for GOP House colleagues while voting against some of his party’s signature legislative efforts.

But party leaders, including House Speaker Nancy Pelosi (D-Calif.), have rallied around him — fearful that a win by challenger Jessica Cisneros could boost the threats to other incumbents, including a trio of powerful committee chairmen who are facing challenges from younger, more liberal candidates this year — Reps. Eliot L. Engel (N.Y.) of the Foreign Affairs Committee, Jerrold Nadler (N.Y.) of the Judiciary Committee, and Richard E. Neal (Mass.) of the Ways and Means Committee.

Cisneros, a 26-year-old human rights attorney, has cast Cuellar as too conservative for an overwhelmingly Democratic district — one that voted for Hillary Clinton over Donald Trump by 20 points in the 2016 presidential race. She has won endorsements from Sanders, Sen. Elizabeth Warren (D-Mass.), Rep. Alexandria Ocasio-Cortez (D-N.Y.) and other leading lights of the left.

The 2020 Super Tuesday primary elections fall on March 3 and encompass 14 states. It's the biggest contest for Democrats seeking their party's nomination. (The Washington Post)

In a call with reporters Friday arranged by Emily’s List, the influential Democratic women’s group that has endorsed her, Cisneros downplayed the ideological dimensions of the primary clash and said her campaign was “about true representation for border communities.”

“We’re still left out of so many decisions and policies that are coming from Washington,” she said.

Also in the crosshairs Tuesday is Rep. Kay Granger (R-Tex.), a former Fort Worth mayor who has risen up the ranks of the House Appropriations Committee since her initial 1996 election to become the top Republican on the powerful panel — and by extension, one of the most powerful GOP women in the House.

But her role as a senior appropriator — one who has had to cut deals with Democrats to pass jam-packed spending bills — has earned her the enmity of her party’s fiscal purists and an aggressive primary challenge in the North Texas-based 12th District from businessman Chris Putnam, who has also highlighted her past position as a supporter of abortion rights.

Putnam’s challenge has been amplified by national conservative groups that see a chance to harden the GOP against government spending by ousting a top appropriator. The anti-tax Club for Growth calls the race a “Republican Upgrade Opportunity” and has funneled more than $1 million into the race.

Endorsing Putnam earlier this year, club president David M. McIntosh noted derisively that Granger was a 12-term incumbent and had “recklessly voted for out-of-control deficit-spending, backroom bloated budget deals, and debt limit increases.”

Voters, he added, “deserve a fiscal conservative with a voting record to match.”

Granger said in an interview that she has tried to sell voters on the importance of her position as a senior appropriator — as well as her December endorsement from President Trump, which has done little to stop Putnam’s claims that he would be the more reliable vote for Trump’s agenda.

“I didn’t expect a primary challenge to try to take out someone in my position, Republican by another Republican,” Granger said. “It does take me by surprise. We should be trying to get the majority back instead of taking out the people who are here.”

Karin Dyer, a Putnam campaign spokeswoman, blasted Granger’s “long record of betraying Republican values during her 24 years in office” and Putnam’s status as “a business outsider that is being attacked by the political establishment, just like President Trump.”

“President Trump needs real allies in Washington, not just ones that show up during campaign season,” she said.

Granger has outraised Putnam by nearly $1.5 million, according to campaign finance reports filed in mid-February, but the spending gap narrowed thanks to the Club for Growth’s spending as well as another $1.1 million spent against Granger from the conservative Protect Freedom PAC.

The Congressional Leadership Fund, the biggest Republican super PAC focused exclusively on House races, made a rare detour into a primary race, spending $1.3 million to help Granger fend off the Club for Growth’s attacks.

Rep. Tom Cole (R-Okla.), a veteran appropriator and a former national campaign chairman for the House GOP, said the race is being closely watched by House leaders and senior lawmakers who fear that governance could suffer if Granger is ousted.

“If all of sudden somebody who supported the president is vulnerable in a primary because they cast tough spending votes, then there won’t be nearly as many people supporting the president when he has to cut a deal, and that’s when Kay’s been there,” he said. “You’re not helping build a Republican majority and you’re not helping the president by beating people like Kay Granger.”

Intraparty tensions are also at play in a pair of Senate primaries in North Carolina and Texas. Democratic Party leaders in Washington are bracing for a close race in the Tar Heel State between their favored candidate, former state senator Cal Cunningham, and a more liberal candidate, state Sen. Erica Smith.

Adding to the intrigue: A super PAC with ties to Senate Majority Leader Mitch McConnell (R-Ky.) admitted last week to spending $3 million on a covert effort to boost Smith — a bid to force Cunningham and his Democratic allies to spend down their campaign accounts, if not eliminate him from the general election entirely.

And in Texas, military veteran M.J. Hegar won plaudits for a strong 2018 House campaign and has, like Cunningham, won the endorsement of the Democratic Senatorial Campaign Committee. But she has struggled to break out amid challenges from labor organizer Cristina Tzintzún Ramirez, state Sen. Royce West, former congressman Chris Bell and Houston City Council member Amanda Edwards, among others.

While Cisneros’s run has invited comparisons to Ocasio-Cortez’s 2018 upset of Rep. Joseph Crowley (N.Y.), then the Democratic Caucus chairman, the comparisons may be superficial. Cuellar, 64, has taken a much more aggressive approach to his campaign than Crowley did, engaging in a ground effort that his allies say is in much closer touch with a politically liberal but culturally conservative district than Cisneros is.

That includes a major fundraising push, drawing heavily on allies in the business world. As of mid-February, the most recent filing deadline, Cuellar had already spent $2.2 million, with another $2 million left in his campaign coffers, while Cisneros spent more than $1 million. Texas Forward, a super PAC supporting Cisneros, has spent another $1.3 million, while unions have added another $200,000 in spending on her behalf.

Supporting Cuellar have been a pair of typically Republican groups: the U.S. Chamber of Commerce and American for Prosperity Action, the campaign arm of the conservative network overseen by industrialist Charles Koch.

The latter group’s involvement, in particular, has fueled sharp attacks from Cisneros and her allies on Cuellar as a “Koch-funded Democrat,” while Cuellar has cast Cisneros’s support for the Green New Deal climate plan as a direct threat to the Texas economy.

“One helps create middle-class jobs; one wants to shut down the oil and gas industry,” said a recent Cuellar ad contrasting the candidates.

Cuellar campaign spokesman Colin Strother said a victory would send a message that “we are a big-tent party.”

“No faction of four or five people and a couple of PACs are going to perform purification rituals on this caucus,” Strother said. “When we have the gavel and we have the speaker, it's because we have a diverse caucus filled with moderates and conservatives.”

For Pelosi, who visited Cuellar’s hometown of Laredo last month for a high-profile fundraiser, the imperative is simple: Stop an insurrection before it spreads, thus insulating other incumbents from costly challenges.

“My role is to win the House for the Democrats and to do so by winning for our incumbents,” she said Friday. “I would like them to get a nice win so that there’s a message for the future, for the next election and the rest — that would be that members who come here, who help us win the majority, will have the support of the leadership of the House.”

Rep. Vicente Gonzalez (D-Tex.), who represents a neighboring South Texas district, was even more pointed, saying he hoped a Cuellar win would send the message “that New York and Massachusetts and California don’t dictate politics in South Texas” — referring to Cisneros’s high-profile endorsers.

“We’re Democrats, strong Democrats, but we’re just a little more moderate than other parts of the country,” he said before echoing a point made by allies of both Cuellar and Granger: “I think it’s very foolish that we’re wasting monumental amounts of resources that we should be using for November.”

But Rep. Pramila Jayapal (D-Wash.), a co-chair of the Congressional Progressive Caucus and one of a handful of House Democrats who have endorsed Cisneros, said no incumbent should feel entitled to their party’s nomination.

A Cisneros victory would send “a message that we should pay attention to our base, that we should pay attention to the need for a member of Congress to stand up for what is right,” she said. “I think every incumbent member, me included, has to always make the case every two years.”

And a Cisneros loss, Ocasio-Cortez said in an interview, wouldn’t mean that other Democratic incumbents could rest easy.

“Underdogs don’t expect to win every time, but that doesn’t mean that we don’t try,” she said.