The other candidates who completed the questionnaire, South Bend, Indiana, Mayor Pete Buttigieg and Sen. Kamala Harris of California, did not commit to either a moratorium on the creation and expansion of factory farms or the restoration of New Deal farming regulations.

The campaign of former Vice President Joe Biden, who entered the race in late April, shortly after Iowa CCI sent out the questionnaire, asked for an extension for adequate time to complete the survey. But the campaign never submitted the form and stopped communicating with Iowa CCI in June, according to the organization.

Of the 24 Democrats currently running for president, just eight chose to complete Iowa CCI’s questionnaire. Rep. Eric Swalwell of California, who dropped out in July , also filled out the group’s survey. Neither billionaire philanthropist Tom Steyer nor former Rep. Joe Sestak (D-Pa.) had entered the race when the questionnaire was due in May.

The presidential hopefuls revealed their views in a candidate questionnaire circulated by Iowa Citizens for Community Improvement, the largest progressive organization in the state that will kick off primary season with its Feb. 3 caucus. The questionnaire, obtained by HuffPost, marks the first time that Warren or Castro has publicly declared support for a halt to factory farm expansion; Sanders’ support for a ban is on his campaign website .

Warren, Sanders, Gabbard, Williamson and Washington Gov. Jay Inslee (D) are also calling for a return to New Deal-style farm regulations, in which the federal government helped farmers manage fluctuations in supply ― and the accompanying price shocks ― by, among other things, buying excess grain and paying farmers to leave fields fallow in fat years.

Five Democratic presidential candidates ― former Housing Secretary Julián Castro, Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.), Rep. Tulsi Gabbard (D-Hawaii) and author Marianne Williamson ― are backing a ban on the creation of new “factory farms” and the expansion of existing ones as part of their efforts to court rural voters frustrated by the effects of industrial-scale livestock operations on their water supply and economy.

Paul Sancya/ASSOCIATED PRESS Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.) are among the presidential candidates to back a moratorium on new factory farms.

Although it would be very difficult for any president to push such a wholesale restructuring of agriculture policy through a Congress that remains either beholden or sympathetic to the agribusiness interests fiercely opposed to the changes, sustainable farming advocates hailed the positive responses as signs that the debate is shifting in their direction.

“What’s exciting from our perspective is that some of these ideas are catching hold, and candidates who are on the ground are actually speaking to farmers and are ... realizing that the system is not working and that rural communities are dealing with polluted water,” said Ben Lilliston, director of rural strategies and climate change at the Minneapolis-based Institute for Agriculture and Trade Policy, a nonprofit that does not endorse political candidates.

Patty Lovera, assistant director of Food and Water Watch, which will eventually endorse a contender through its political arm, called the affirmative responses to the agriculture policy questions a sign of “progress.”

By contrast, she warned candidates who decline to make firmer commitments: “Just pledging to love family farms is not really a policy.”

The full text of the questionnaire and the candidates’ responses, which cover a range of topics from “Medicare for All” to climate action, is available on a dedicated webpage erected by Iowa CCI.

Iowa CCI, in conjunction with People’s Action, the network of liberal groups of which it is a part, plans to host a presidential candidate forum on Sept. 21 in Des Moines, Iowa, for top-polling candidates who completed the questionnaire. Iowa CCI will likely roll out its presidential candidate endorsement in October.

In addition to responses on agricultural policy, there were other notable omissions from participating candidates.

Neither Harris, Buttigieg nor Inslee responded with a clear affirmative when asked whether they would sign Iowa CCI’s letter in support of a Des Moines racial-profiling ban favored by civil rights groups. The Iowa-Nebraska NAACP wants to ban the use of racial profiling by city police with a measure to require Des Moines to create a civilian review board and maintain data on the racial makeup of traffic stops and other police interactions, while the City Council is pushing an ordinance without those two provisions. (The remainder of the candidates said they would sign the letter.)

Harris and Gabbard were alone among the candidates in declining to offer a firm response when asked whether they would back the repeal of an Iowa state law (S.F. 481) that prevents municipalities from becoming “sanctuary cities,” which limit their cooperation with federal immigration authorities.

The questionnaire’s effort to gauge candidate views on issues like factory farming, seen as traditionally germane to rural white voters, as well as concerns about police bias and immigration enforcement, seen as most relevant to communities of color, reflects Iowa CCI’s interest in building an interracial, working-class coalition capable of propelling Democrats to victory on a progressive platform.

Though Iowa CCI does not state it explicitly, the populist, social justice-centric approach stands in contrast to the moderate tactics promoted by some Iowa Democrats who see the party’s biggest growth areas in the state’s affluent suburbs ― particularly in Des Moines. Both of the Democrats who flipped GOP-held U.S. House seats in Iowa last November, Cindy Axne and Abby Finkenauer, are from the party’s more moderate wing.

Iowa is not racially diverse statewide, but African Americans make up 10% to 15% of the populations in Des Moines, Waterloo and Cedar Rapids. And the growing Latino immigrant population, which arrived to fill agricultural and meatpacking jobs, has raised generations of U.S. citizens now eligible to vote. Even a modest uptick in turnout from either demographic group could make the difference in a general presidential election where Iowa remains a battleground.

At the same time, in Iowa’s vast rural plains, the fallout from President Donald Trump’s trade war with China, which has blocked American farmers’ access to its markets, has prompted some farmers to reconsider their support for the president.

Progressive organizers and sustainable agriculture advocates see the fraying of Trump’s bond with normally Republican farmers as an opportunity to reopen a discussion of over four decades of agriculture policies that they believe have been devastating to family farmers and the environment.

Lax antitrust enforcement has allowed factory farms ― also known as concentrated animal feeding operations, or CAFOs ― to skyrocket in Iowa since the 1980s. The number of Iowa hog farms dropped by 82% from 1982 to 2007, even as the number of hogs sold, on average, by each farm grew more than tenfold, according to a Food and Water Watch analysis of official data.

The result has been a concentration of animal waste and chemicals in Iowa’s waterways that is the source of serious health problems, including cancer. Once the chemicals are in Iowa’s water sources, they flow down the Mississippi River to the Gulf of Mexico, where they are a significant contributor to the massive fish and plant life dead zone off Texas and Louisiana.

Meanwhile, with far fewer meat companies to whom to sell their commodity crops, farmers have less leverage to command a price that helps them afford their livelihoods. Farmers now earn just 14.6 cents for every dollar Americans spend on food ― a 17% decline since 2011 and the lowest figure since the federal government began counting in 1993.