Democrat Colin Allred is running for the 32nd Congressional District seat in Texas. (Allison V. Smith/For The Washington Post)

 The largest number of Democratic congressional candidates in decades is putting into play dozens of House districts across the country, raising the possibility of a bitterly contested midterm election cycle next year as the party and its activists try to take advantage of President Trump’s unpopularity to win a majority in the House.

Yet these candidates and their supporters are also waging a battle among themselves about what the Democratic Party should stand for. After a string of defeats in special elections this year, activists across the country are pitted against Washington-based leaders and strategists about what the message and the tactical plan should be to win the 24 seats needed to take control of the House.

Democrats as well as independent observers believe that figure is attainable given historical trends, Trump’s and the congressional GOP’s sustained unpopularity and the ballooning number of candidates with gold-plated résumés willing to run.

What they don’t agree on is how to do it — by exciting the base with a liberal economic message and fiery candidates in the model of Sen. Bernie Sanders (I-Vt.), or by keeping the party’s doors open to moderates and independents with centrist contenders, ideally with business or military experience.

Following this year’s losses, neither faction can say they’ve proved how to win.

Democrat Ed Meier is running for the 32nd Congressional District seat in Texas. (Allison V. Smith/For The Washington Post)

“I think there is a massive amount of demoralization with the American people with the Democratic Party, with the Republican Party,” Sanders said on “Meet the Press” on Sunday. “What the Democrats have got to say is that, ‘We will be on the side of the working class in this country.’ ”

The battle over the path forward is raging across the country in dozens of races. Several districts that had seen only token candidates, or no candidates at all, in the past are suddenly packed with mostly first-time Democratic contenders with a broad variety of backgrounds and qualifications. Among them: veteran Jason Crow in Colorado, stem-cell researcher Hans Keir­stead in California, Democratic State Sen. Jennifer Wexton in Northern Virginia, former gubernatorial aide Gareth Rhodes in Upstate New York and former sneaker company executive Chrissy Houlahan in Pennsylvania.

Democrats can exceed their past performance in at least 70 House districts across the country controlled by Republicans, primarily because more Democrats registered to vote, said Rep. Ben Ray Luján (D-N.M.), chairman of the Democratic Congressional Campaign Committee, in a memo to his colleagues last week.

Luján added that the party is not struggling to recruit candidates.

“In recent cycles, candidate recruitment meant dialing the phone and asking people to run. This cycle, it’s about answering the calls when they come in,” said Nathan Gonzales, editor of Inside Elections, a nonpartisan newsletter that tracks congressional races.

Yet Democrats remain skittish about their chances, given their poor record so far this year. Candidates and strategists watched warily last week as one of their own, 30-year-old Jon Ossoff, lost an exorbitantly expensive and closely watched special election in suburban Atlanta to Republican Karen Handel. After starting his race vowing to “make Trump furious,” he avoided attacks on the president during the general election, believing that a less partisan message would win over independents.

It didn’t. And party leaders found themselves trying to explain how the party fell short in a wealthy suburban district they believed they could win — and how they are still well-positioned for next year.

Sen. Bernie Sanders (I-Vt.) rallied in Pittsburgh on Saturday to demand that Sen. Pat Toomey (R-Pa.) vote against the Republican health-care plan. (Jason Merritt/Getty Images For Moveon.Org)

“The national environment, unprecedented grass roots energy and impressive Democratic candidates stepping up to run deep into the battlefield leave no doubt that Democrats can take back the House next fall,” Luján wrote in his memo.

In many swing districts across the country, the glut of Democratic candidates is setting up primary fights in expensive media markets that will draw resources away from defeating Republican incumbents. 

In Northern Virginia, at least seven Democrats are planning to run against Rep. Barbara Comstock (R-Va.) in a district that Hillary Clinton won by 10 points. At least seven are also running against Rep. John Faso (R-N.Y.), who represents most of New York’s Hudson Valley. At least four are considering runs against Rep. Daniel Donovan (R-N.Y.) on New York’s Staten Island, while least a dozen are mulling bids to replace retiring Rep. Ileana Ros-Lehtinen (R-Fla.) of Miami.

Gonzales said that the emerging dynamic for Democrats mirrors what happened to Republicans during the tea party wave of 2010. “They’re going to have some expensive and ugly primaries, but that also doesn’t mean they can’t take back majorities in Congress,” he said.

Here in Dallas, first-time candidate Colin Allred, a former NFL linebacker for the Tennessee Titans and civil rights attorney, is running against Rep. Pete Sessions (R-Tex.) in a district where Clinton narrowly won last year and Sessions faced just token opposition. Allred has spent the past six weeks hosting “Coffee with Colin” at local coffee shops on Thursday nights and Saturday afternoons, which he says draw as many as 60 people.

Allred believes the contest will be shaped by economic concerns, health care and other “kitchen table issues.” That means focusing on solutions — not on lobbing attacks against Trump or Republicans.

“I’ve never gotten a question on Russia,” Allred said. “I get very few questions about Trump, period.” That’s because for many people here, Trump “is an ever present issue.”

He added: “People in this area that I talk to have come to terms with Trump and are now interested in the next step, and they want a vision for the future.”

Ed Meier, a former State Department official and another first-time candidate, is also planning to run against Sessions. How Meier and Allred will distinguish themselves from each other is less clear. Both were born and raised in the district and did stints in the Obama administration. Neither would draw distinctions with the other on policy or personality.

And other local Democrats are still mulling a run, meaning the field could become even more crowded soon.

“The Trump administration is coming in and is working to tear down the progress that happened in the Obama administration,” Meier said. “We as Democrats need to come back and build back better, build back stronger, be bolder with what our agenda looks like.”

Other factors that could play a role in that contest are race and minority outreach. The Democratic Party has long tried to recruit more candidates of color, such as Allred, to help draw out the party’s base of voters. Which candidate is able to raise more money will also play a role.

Jesse Hunt, national press secretary for the National Republican Congressional Committee, warned that the crowded fields will cause “a natural gravitational pull to the left” that results in Democratic candidates being less palatable to voters in GOP-held districts.

“Any appearance of putting their thumb on the scale for their more establishment-friendly candidate is only going to further enrage the base voters who were wronged in the last cycle,” Hunt said.

In Dallas, Allred and Meier are running in the 32nd Congressional District, which stretches from city neighborhoods to the suburbs, combining mom-and-pop diners, Paneras, mostly white enclaves and other areas packed with Jewish, Latino, Muslim and black families. 

Allred, 34, held several roles in the Obama administration, including in the White House Counsel’s Office and as an aide to former Housing and Urban Development secretary Julián Castro. Meier, 40, is an earnest dad who wears hipster glasses and worked at the State Department managing the logistics of the U.S. military drawdown in Iraq. He also worked on the transition team for a Clinton presidency that never happened.

Allred said he believes Democrats have a chance here in part because Clinton won the Sessions district “with zero organization here and zero money.”

Meier said he has heard from Clinton, who is urging former supporters and staffers to run for office. He said he would welcome her to the district. 

“She won the district by two points over Donald Trump and could be a tremendous asset,” he said. “It might be nice,” he added, for her to help raise money as well.

Texas’s 7th District, a wealthy and diverse stretch of Houston suburbia, resembles the one where Ossoff lost in Georgia — and popped onto the Democrats’ 2018 map after Clinton beat Trump by 1.3 points.

Laura Moser, a progressive activist who launched the group Daily Action to stop Republicans and Trump, moved back to run in the 7th District from Washington this month — despite her view that she’s not the D.C. establishment’s dream candidate.

 “They have very conventional ideas of who can win — business people who’ve been on this path for a long time,” Moser said in an interview at her new home. “I’d say this: I did not get any encouragement from the DCCC.”

She also faces lots of competition. James Cargas, an environmental attorney, raised less than $100,000 for his third bid against Rep. John Abney Culberson (R-Tex.) last year — and lost the race by single digits. A total of six competitors have jumped in to grab the baton, but he hasn’t dropped it, arguing that he’s been hardened by five lonely years on the trail.

“There’s 700,000 eligible voters in this district,” Cargas explained. “You can’t just meet ’em once — you have to meet them multiple times. That takes retail and hard work.”

Young candidates are taking on more than Republican opponents. In the wake of Ossoff’s loss, House Speaker Nancy Pelosi is once again in the crosshairs of ambitious younger House Democrats already talking openly about the possibility of challenging her ahead of next year’s elections to remove the subject of tens of millions of dollars in attack ads that continue to work well for Republicans. 

Asked about Pelosi, several of the new candidates sought to minimize her importance.

“I’ve taken hundreds of questions from hundreds of folks and nobody has ever brought up Nancy Pelosi. No one brings her up,” Allred said. 

Weigel reported from Houston. Jenna Portnoy in Washington contributed to this report.