Andrew Melman has been spending his Saturdays wearing a forest green League of Conservation Voters T-shirt while knocking on doors in the wealthy, well-educated and electorally crucial Philadelphia suburbs.

He met two different men who answered their doors and told the same story: Their wives were out working on the Democratic campaign, but they were indifferent. “They just didn’t like any of the candidates and weren’t going to vote,” Melman said. Of course, this is exactly why Melman was here, working off a list of unreliable Democratic voters.

“I said, ‘Do you have kids? Do you care about climate for them? Well, how about supporting your wives by voting with them?'” Melman said. “By end of the conversation, both of them said they would at least think about it. So maybe I turned a vote or two. We’ll see.”

Melman, a 66-year-old electrician and small business owner, is one of hundreds of volunteers and staffers for environmental organizations who have been working in swing states across the country to get out the vote for Hillary Clinton and Democrats down the ballot. The League of Conservation Voters (LCV), Sierra Club, NextGen Climate and other green groups say they have invested record mutimillion-dollar sums in person-to-person campaigning this year.

By and large, those groups have not succeeded in pushing climate and environmental issues into the campaign conversation. By one estimate, climate and energy issues were discussed for a grand total of 5 minutes, 27 seconds in the three presidential debates, part of that was an exchange over whether global warming is real or not. The campaign has been dominated by issues such as Donald Trump’s treatment of women and Clinton’s email controversies.

To environmentalists, there is no worse option than Trump, who denies climate change, and while some feel Clinton has not championed their goals as they would like, they at least believe she will respond to pressure on those issues when she is in office.

So, activist groups are turning to the “ground game” to make that happen: phone banking and canvassing door-to-door. They are prodding people to vote early and coordinating rides to the polls on Election Day.

“In this election, a lot of people are unhappy with the lack of substance on the issues,” said Tiernan Sittenfeld, senior vice president of government affairs for LCV. “When our members are out there, knocking on doors and talking about why they are voting for Hillary Clinton or our other candidates, I think that sends a very powerful message.”

Sierra Club deploys some of its 600-person staff full-time to reach out to some of the group’s 1.2 million members in the campaign’s final weeks through its Victory Corps program.

Melissa Williams, a regional spokeswoman for Sierra Club’s Beyond Coal campaign, is finding her voice put to the test making calls in North Carolina.

Working a phone list of Sierra Club members that includes Republicans and unaffiliated voters as well as Democrats, Williams said she talks about the state’s struggles managing coal ash waste and the devastation wrought by Hurricane Matthew, while voters voice concerns about fracking and pipelines. “They look out their windows, and they want to protect their viewsheds, they want to protect their trout streams,” Williams said.

“My goal is to get them to think about what’s important to these mountains,” she said. “Please don’t just vote about who’s in the White House. Vote for these mountains as well.”

Williams is finding the people on her call list receptive to that message. “One woman said she’s writing in ‘Jesus Christ’ for president, she wants to make sure she keeps her guns, and she thinks vaccines cause autism, but she’s sure enough going to vote for our candidates in her district,” Williams said. “Well, that sums up the mountains, right there.”

Perhaps no get-out-the-vote effort is as ambitious as the $25 million drive to reach young voters by NextGen Climate, the nonprofit founded by hedge fund billionaire-turned-activist Tom Steyer. The group sent staff to 300 colleges and universities in 13 states and says it has registered 295,000 millennial voters.

NexGen canvassers brought their clipboards to high-traffic areas, outside dining halls or libraries and at Grand View University in Iowa, set up a stand for students to make candy apples while talking about voting. At Loyola Chicago, they worked the lines at Taco Tuesdays. Using the data collected, NextGen so far has sent out more than 3 million text messages to young voters, focused on getting them to the polls.

At the polling place on the campus of College of Southern Nevada, NextGen literally rolled out a red carpet to the door, while Las Vegas hip hop/funk/jazz band The Lique played outside on a stage festooned with a red banner that read, “Climate is our Candidate.”

“A lot of our election effort is aimed at making the actual experience of voting something that’s fun, enjoyable, and something that you do with your peers,” said Zack Malitz, NexGen’s national campus program director.

The League of Conservation Voters has invested $1.8 million in its GreenRoots program, mobilizing 2,000 of its volunteers and 82 staff members in 11 swing states.  

“The thing that we’re up against is so many highly educated people have had their minds poisoned,” said Gayle Bell, a volunteer for LCV in Winter Park, Fla. She said she knows there’s not much she can do to persuade someone who says that Clinton “should be in jail.” But when she hears a voter say, “I don’t like either candidate,” Gayle said she sees that as an opening. She tells them how she was a Bernie Sanders supporter, and also considered not voting, or voting for a third-party candidate. But then she realized either course of action would be the equivalent of a vote for Trump, which is why she decided not only to vote for Clinton, but to volunteer, too.

Jerry Bell, Gayle’s husband and a retired Air Force engineer, said he focuses on the message of a clean energy economy, and for those who aren’t struggling as hard economically, Jerry said he delivers what he calls “the John F. Kennedy message.”

Melman has found his door-to-door work in the Philadelphia suburbs more satisfying than making phone calls.

“Some people I could tell were at home and weren’t opening their doors, but the people who answered were pretty receptive,” Melman said. “One person said, ‘You’re the fourth person who’s been by today,’ and I saw all the paraphernalia there from other campaigns.”

Melman, who installs solar panels in addition to other home electrical work, believes the renewable energy business has been hurt because it lacks a level playing field with fossil fuels.  He is convinced Democratic Senate candidate Katie McGinty will help change that if she beats Republican incumbent Pat Toomey. “He’s pro-coal and pro-oil, and he doesn’t think renewables are a solution. And unfortunately, I think that’s the mindset of a lot of people in Pennsylvania,” he said. “Our state is really divided.”

The success of the Obama campaign’s ground game in 2008 and 2012 has spurred environmental groups and others to focus on face-to-face field operations, said Sasha Issenberg, author of the 2012 book, “The Victory Lab: the Secret Science of Winning Campaigns.”

Issenberg said the groups have to show the candidates that they made a difference. “It’s about turning out Democratic voters, but it’s also about making sure the candidate feels indebted to you,” Issenberg said. “You want Katie McGinty to know ‘I couldn’t be here without the help of the environmental groups. So she remembers that when she’s thinking, ‘Which liberal interest group can I least afford to piss off?'”

The ground game, in other words, doesn’t end on Election Day. In particular the strategy with Clinton is for the major green groups to help get her elected, and then pressure her to follow through with actual policy.