While some Democrats were basking in the “joy” that Vice President Kamala Harris has brought to the campaign trail and running mate Tim Walz’s put-downs of Donald Trump’s “weird” antics, a select group of politically engaged pro-housing activists who are part of the self-described “Yes in My Backyard” (YIMBY) movement were celebrating something a little more prosaic: Harris’ promise, in a mid-August stump speech, to “take down barriers and cut red tape” that block housing construction and see 3 million new homes built in her first term as president.

The promise, and its high profile at the convention, amounted to a coming-out party for YIMBYism within the Democratic Party, as an idea long embraced by some of the party’s leading thinkers finally met its political moment.

“This is the root cause of expensive rent,” said Bharat Ramamurti, who served as the deputy director of the National Economic Council under President Joe Biden. “I think the core idea of increasing supply and looking at ways the federal government can do that has been the mainstream Democratic position.”

So what elevated it to the top of Harris’ agenda? Politics. Housing costs are a mainstream political issue in a way they simply weren’t during President Barack Obama’s tenure and are a key issue in the swing states of Nevada and Arizona, where rent and home prices have spiked since the coronavirus pandemic.

“The need for more housing is existential in Nevada,” Zach Conine, the Nevada state treasurer, told HuffPost in a phone interview. “It’s existential in Las Vegas, in Reno and in small towns across the state. From a Nevada perspective, anything you can do that increases supply is certainly worth considering making an investment in.”

Obama’s shoutout to increased housing supply at the convention was just the cherry on top for YIMBY partisans.

Harris “knows, for example, that if we want to make it easier for more young people to buy a home, we need to build more units and clear away some of the outdated laws and regulations that have made it harder to build homes for working people in this country,” Obama said. “And she’s put out a bold new plan to do just that.”

Obama had also presented just such a plan shortly before leaving office in 2016, but this is likely the first time the issue has taken center stage in a presidential election.

The YIMBY movement is an ideologically diverse response to the phenomenon of state and local governments limiting how much housing can be built through zoning and land-use laws that contribute to sky-high rental and home purchase costs. These restrictive housing laws are propped up by the quietly influential, bipartisan bloc of homeowners known derisively by their critics as “Not in My Backyard” activists, or NIMBYs.

Although Democrats at the national level, including Obama, have been warming to YIMBYism for years, these federal officials have far less control over housing than their state- and local-level counterparts. YIMBYs instead hope the high-profile shoutouts to their cause will give them new leverage as they continue to lock horns with housing development opponents ― many of them Democrats ― in their home cities and states.

“This offers huge political momentum for the YIMBY movement that Obama started and we lost track of in 2016,” said Matthew Lewis, a spokesperson for California YIMBY, the arm of the YIMBY movement in the country’s most-populous state. “I hope it helps to highlight the challenges within our party” between proponents and opponents of more home construction.

Wednesday night offers an initial chance for YIMBYs to build upon their new momentum with a “YIMBYs for Harris” video livestream and fundraiser designed to mirror events held by numerous other Democratic groups. The event is both an opportunity to demonstrate the importance of the YIMBY constituency within Harris’ camp and draw additional attention to the YIMBY cause. Top speakers are slated to include Govs. Wes Moore (Md.) and Jared Polis (Colo.); Sen. Brian Schatz (Hawaii); Reps. Scott Peters (Calif.), Robert Garcia (Calif.), Maxwell Frost (Fla.) and Brittany Pettersen (Colo.); and San Francisco Mayor London Breed.

Armand Domalewski, a San Francisco data scientist, and fellow YIMBY activists actually first formed “YIMBYs for Harris” ― the core of which is a private WhatsApp group with more than 300 participants ― after Harris selected Minnesota Gov. Walz, whom they see as a housing champion, as her running mate in early August. In spite of Democrats’ trifecta in Minnesota, legislation overriding restrictive zoning in the state fell short earlier this year, even as other measures, like affordable housing funding and additional tenant protections, became law.

“We wanted to have a big display of, ‘Hey, this is where the Democratic Party’s at. If you’re a Democratic Party elected official, jump in, the water’s warm. It’s safe to be a YIMBY. It’s good to be a YIMBY. Kamala Harris is a YIMBY,’” Domalewski said.

“It’s super important to send that message to Kamala Harris,” he added.

There are clear limits to how much Harris is embracing YIMBYism, however. Her campaign has avoided using the term, and it was Obama rather than the vice president herself who specifically called out zoning laws as needing reform. But it’s also clear that she and the YIMBY movement share the same broad goal: making housing more affordable by increasing the supply of homes.

Indeed, proposals to increase housing supply at the local level often generate fierce opposition in Democratic states, including California, New York, Connecticut and Maryland. Homeowners ― many of whom have otherwise liberal politics ― cite fears of increased traffic, overcrowded schools and crime spikes to argue against new and denser housing in their neighborhoods.

Conine, a Democrat, was one of dozens of local and state officials to hold events this week in key swing states to hype the Harris campaign’s housing plan, holding a news conference in Reno alongside a building trades union leader. In an interview, he went further than the Harris campaign did in embracing the underlying logic of YIMBYism.

“We as a community, we as a society, cannot get into the perfect home and then turn around and shut the door behind us,” he said. “We all have to be comfortable that if Nevadans, people around the country, are going to find someplace to live, that’s going to mean building more units, which means they have to go somewhere, right?”

“And the benefit to our community and society, the benefit to our economy from having people housed as opposed to unstable, that should outweigh any frustrations about increased traffic or a view getting slightly disrupted,” Conine said.

Harris has framed her support for increasing the supply of housing as more personal than ideological. In an ad her campaign released this week, Harris relates the story of how her mom saved for “well over a decade” to buy a home.

Harris promotes her work suing big banks in the wake of the 2008 financial crisis and her plan to ban corporate landlords from buying up houses before discussing the YIMBY-esque elements of her plan to lower housing costs.

“We will end America’s housing shortage by building 3 million new homes and rentals,” Harris says in the 30-second ad. “We should be doing everything we can to make it more affordable to buy a home, not less.”

Obama likewise had both the substance of the housing affordability issue in mind and its political potency when he delivered his remarks Aug. 20 at the Democratic National Convention.

“As President Obama said, Democrats must restore people’s confidence in a democracy that not everyone feels is working for them,” said Eric Schultz, a spokesperson for the former president. “We know there was a crisis of affordability in this country long before the pandemic sent inflation soaring.”

“The cost of housing is still too high, even if you have a good job with decent pay,” he added. “That’s why he’s proud that Vice President Harris has a plan to make it easier to build more housing that will be more affordable for more people.”

The GOP’s housing plans have not put a central focus on building new homes or relaxing zoning restrictions, with Trump’s vice presidential nominee, Sen. JD Vance (Ohio), often suggesting illegal immigration has been a cause of increased home prices, a contention largely dismissed by housing advocates and economists.

“The Democrats flooded this country with millions of illegal aliens,” Vance said in his speech last month at the Republican National Convention. “So citizens had to compete — with people who shouldn’t even be here — for precious housing.”

Right now, however, it appears voters prefer Harris’ YIMBY-backed approach to the problem. A YouGov poll released earlier this month found that 40% of voters thought Harris was the candidate more likely to lower housing costs, while 36% said Trump was.

Still, the YIMBY movement sees its bipartisan appeal as one of its strengths. Deregulation is, after all, traditionally a Republican ideal. Sen. Todd Young (R-Ind.), for example, has collaborated with Schatz on federal legislation discouraging restrictive zoning.

In a highly polarized moment, might the very idea of a “YIMBYs for Harris” group risk turning Republicans against the idea?

Domalewski sees it differently, reasoning that a display of enthusiasm can show candidates and lawmakers from both parties the political gain to be reaped by getting on board.

“What I’d like it to be is a competition” for YIMBY votes, he said.