DES MOINES, Iowa — Rep. Eric Swalwell Eric Michael SwalwellSwalwell calls for creation of presidential crimes commission to investigate Trump when he leaves office 'This already exists': Democrats seize on potential Trump executive order on preexisting conditions Swalwell: Barr has taken Michael Cohen's job as Trump's fixer MORE (D-Calif.) came to Miami to throw haymakers. The young congressman used his few minutes at last week’s debate to take on both the front-runner in the race for the Democratic presidential nomination, and a chief rival, South Bend, Ind., Mayor Pete Buttigieg Pete ButtigiegBillionaire who donated to Trump in 2016 donates to Biden The Hill's Morning Report - Sponsored by Facebook - GOP closes ranks to fill SCOTUS vacancy by November Buttigieg stands in as Pence for Harris's debate practice MORE, who also aims to win over younger voters.

The night before, former Housing and Urban Development Secretary Julián Castro engaged in the sharpest exchange of the evening with former Rep. Beto O’Rourke (D), a fellow Texan whose star has dimmed in recent months.

ADVERTISEMENT

On both nights, some of the most contentious moments came when candidates seeking to break out of the 1-percent pack took aim at those polling just ahead of them, highlighting a fierce and growing competition to own particular constituencies within a fragmented field.

“A number of lower-tier candidates used the debates to try to climb into the top five, both by owning an issue and going after the candidate that is competing most directly for their segment of voters,” said Ben LaBolt, a veteran of former President Obama’s 2012 reelection campaign.

The lesson many observers, and the candidates themselves, took away: While former Vice President Joe Biden Joe BidenPelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Hillicon Valley: Subpoenas for Facebook, Google and Twitter on the cards | Wray rebuffs mail-in voting conspiracies | Reps. raise mass surveillance concerns Fox News poll: Biden ahead of Trump in Nevada, Pennsylvania and Ohio MORE is likely to weather the highest number of slings and arrows, no one is safe from attack.

Those watching the contest with a keen eye say the aim is to carve out a niche within the field — and to kneecap anyone who competes for that niche, whether they are a front-runner or an also-ran.

“When you’re struggling for attention and there’s a field this crowded, standing out anywhere helps. So you don’t necessarily need to take out a top-tier candidate, because chances are you won’t be able to. But you can still distinguish yourself and position yourself as the top of that tier, the next person ready to break out,” said Mo Elleithee, a former spokesman for the Democratic National Committee who now heads the Institute of Politics and Public Service at Georgetown.

Swalwell, 38, is angling to corner the millennial market. He urged Biden, 76, to “pass the torch” to the next generation of leaders. Minutes later, he took aim at a rival who has made his own inroads among the youngest cohort, Buttigieg, over a police shooting that left a young black man dead. Swalwell told Buttigieg he should have fired the police chief; Buttigieg stared daggers in cold, silent response.

Castro, another candidate polling near 1 percent, sees O’Rourke as a chief rival, even as O’Rourke’s star has dimmed. Castro challenged O’Rourke’s knowledge of immigration policy, eroding one of the former congressman’s most important issues.

Each time a party’s presidential nomination is up for grabs, candidates who do not begin as front-runners tend to begin by defining their own lanes.

In 1992, former Sen. Paul Tsongas (D-Mass.) made himself the deficit hawk, and then-Arkansas Gov. Bill Clinton William (Bill) Jefferson ClintonAnxious Democrats amp up pressure for vote on COVID-19 aid Barr's Russia investigator has put some focus on Clinton Foundation: report Epstein podcast host says he affiliated with elites from 'both sides of the aisle' MORE aimed to win over centrist Democrats. In 2004, former Vermont Gov. Howard Dean (D) raced to the top of the pack when he cornered anti-war voters. In 2016, Sen. Ted Cruz Rafael (Ted) Edward CruzThe Hill's Morning Report - Sponsored by Facebook - Trump previews SCOTUS nominee as 'totally brilliant' Cruz blocks amended resolution honoring Ginsburg over language about her dying wish Trump argues full Supreme Court needed to settle potential election disputes MORE (R-Texas) staked out a position as the most conservative Republican, while Ohio Gov. John Kasich (R) presented himself as the man in the middle.

This year, with a field so varied, the lanes are more narrow. Castro and O’Rourke are competing to be the prime Texan and the top voice on immigration reform. Washington Gov. Jay Inslee Jay Robert InsleeBarr asked prosecutors to explore charging Seattle mayor over protest zone: report Bottom line Oregon senator says Trump's blame on 'forest management' for wildfires is 'just a big and devastating lie' MORE (D) has centered his pitch solely on combating climate change. Sens. Michael Bennet Michael Farrand BennetOVERNIGHT ENERGY: House Democrats tee up vote on climate-focused energy bill next week | EPA reappoints controversial leader to air quality advisory committee | Coronavirus creates delay in Pentagon research for alternative to 'forever chemicals' Senate Democrats demand White House fire controversial head of public lands agency Next crisis, keep people working and give them raises MORE (D-Colo.) and Amy Klobuchar Amy Klobuchar3 reasons why Biden is misreading the politics of court packing Social media platforms put muscle into National Voter Registration Day Battle lines drawn on precedent in Supreme Court fight MORE (D-Minn.) are competing with Biden for the centrist slot. And Sen. Kirsten Gillibrand Kirsten GillibrandSunday shows preview: Justice Ginsburg dies, sparking partisan battle over vacancy before election Suburban moms are going to decide the 2020 election Jon Stewart urges Congress to help veterans exposed to burn pits MORE (D-N.Y.) is trying to carve out a niche as the candidate for female voters.

“If you’re occupying the same lane as another candidate, you have to get them out of the way before you’re a contender for the broader field,” said Stephanie Cutter, a veteran of both Obama’s and Hillary Clinton Hillary Diane Rodham ClintonFox News poll: Biden ahead of Trump in Nevada, Pennsylvania and Ohio Trump, Biden court Black business owners in final election sprint The power of incumbency: How Trump is using the Oval Office to win reelection MORE’s campaigns. “Otherwise, you’re competing for the same votes in a very crowded primary.”

Inslee, one of three straight, white male governors in the race, has been the most aggressive at defining himself as better than his two rivals. He says he has a more progressive record than either Montana Gov. Steve Bullock Steve BullockMcConnell locks down key GOP votes in Supreme Court fight Senate Democrats demand White House fire controversial head of public lands agency Pence seeks to boost Daines in critical Montana Senate race MORE (D) or Colorado Gov. John Hickenlooper John HickenlooperThe Hill's Morning Report - Sponsored by Facebook - Trump previews SCOTUS nominee as 'totally brilliant' Cook Political Report shifts Colorado Senate race toward Democrat Willie Nelson playing at virtual fundraiser for Hickenlooper MORE (D) — especially on climate change.

“I'm the guy who banned fracking. There might be another couple of governors on the stage. They've done the opposite, they've embraced fossil fuels. I don't believe that's our future, so I'll have a different view from the other executives,” Inslee told The Hill last month.

ADVERTISEMENT

Speaking to voters this weekend in Des Moines, Inslee, who used to run a farm in eastern Washington, joked he is also better at bucking hay than Bullock.

Some Democratic strategists warn that owning a lane may be less effective today than it has been in the past, especially when front-running candidates like Sens. Elizabeth Warren Elizabeth WarrenHillicon Valley: Subpoenas for Facebook, Google and Twitter on the cards | Wray rebuffs mail-in voting conspiracies | Reps. raise mass surveillance concerns On The Money: Anxious Democrats push for vote on COVID-19 aid | Pelosi, Mnuchin ready to restart talks | Weekly jobless claims increase | Senate treads close to shutdown deadline Democratic senators ask inspector general to investigate IRS use of location tracking service MORE (D-Mass.) and Kamala Harris Kamala HarrisHundreds of lawyers from nation's oldest African American sorority join effort to fight voter suppression Biden picks up endorsement from progressive climate group 350 Action 3 reasons why Biden is misreading the politics of court packing MORE (D-Calif.) seem to cross so many lanes.

“I think the challenge is that there aren’t a lot of single-issue voters in the Democratic primary,” said Tom Bonier, a Democratic analytics expert. “Winning traction on a single issue can provide a toe hold for a candidate to draw more attention from potential supporters, and that’s likely the strategy behind that line of thinking.”

Those polling so far behind the front-runners have just one more chance to vault into the top tier, when they meet for debates later this month in Detroit on CNN.

The next debates in the fall will cull the field to just 10 candidates, including only those who reach higher polling and donor thresholds after the Democratic National Committee doubled the criteria for qualification from the June and July events.

It is unlikely that Castro, Swalwell, Inslee or Gillibrand will take out Biden — but their immediate concern is not beating Biden. It is securing a harder-to-obtain spot on the debate stage for the third round.

They can earn that spot by eliminating others eager for a spot on stage, rather than the front-running candidates.

“Draw distinctions where you can, and it doesn’t have to be with a top tier candidate,” Elleithee said. “You don’t see a lot of mid-ranked fighters take the title shot the next time out.”