An umbrella organization of labor and progressive groups is ramping up on-the-ground operations in an attempt to propel Hillary Clinton and like-minded Democratic candidates to victory this fall. And they’re getting a multi-million-dollar cash infusion from one of the party’s biggest donors.

For Our Future PAC, a 501c4 and super PAC organization, is aiming to knock on 5.3 million doors between now and Election Day in a variety of battleground states, representatives of the group told The Huffington Post. The group, which has already reached 2 million households, is the creation of leading labor groups and billionaire environmentalist Tom Steyer, who announced on Tuesday that his group NextGen Climate was donating an additional $15 million to the cause on top of the $5 million it has already given. For Our Future PAC’s total budget is now $55 million after starting with a $50 million objective.

The investment in Get Out The Vote operations represents a huge bet that a conventional campaign playbook still matters in this highly unconventional election. With Donald Trump banking on free media and his powers of persuasion to win the presidency, progressives are turning to old-fashioned door-knocking.

“Real change happens through real people and you have to get people where they actually are which requires conversations on the issues they care about,” said Amanda Brown, campaign director for For Our Future PAC. “When there are billions of dollars poured into TV and radio ads, those just don’t hit home in the same way. I think, also, given the nature of the candidates we are choosing between this cycle, what you see on the air is heavy on persuasion, convincing people they have to vote. The work we are doing is to try and empower individuals and make them understand that their power is voting.”

At its inception, For Our Future caused discord within labor ranks, as several building trade unions scoffed at the alliance with a donor known for his environmental-based opposition to major energy projects like the Keystone Pipeline. But a close election has a way of quieting discord. And the group appears to be gearing up in the closing weeks of the campaign.

As part of its ramped up ground game, For Our Future has expanded its operations to Missouri and North Carolina in addition to work being done in Nevada, Wisconsin, Ohio, Pennsylvania and Florida (all, tellingly, with Senate races this cycle). Its staff currently numbers more than 700, with the vast majority in those swing states.

Though Trump has largely passed on building a robust campaign apparatus, an investment in on-the-ground organizing for Democrats does not come without challenges. The party faces significant hurdles with white working-class voters drawn to Trump’s message, millennials turned off by Clinton, and some of the coalition that helped elect Barack Obama twice proving difficult to re-mobilize. To combat that, For Our Future has brought together different entities with ties to unique constituencies.

The group, for instance, is working with the NAACP as well as Color of Change to engage black voters and bolster community-based activism. It is working with VoteVets, a progressive veterans organization, to do more door-to-door campaigning in addition to its traditional focus on paid media. And, according to notes provided to The Huffington Post, it is assisting several state-specific organizations to micro-target groups of voters. That list includes Make it Works Nevada, Ohio Environmental Council, Equality PA, and Wisconsin Jobs Now.

“The whole idea is building power up,” said Brown. “So there are a ton of great organizations who have been on the ground in these communities doing work for longer than I’ve been alive. What we are not doing is saying you have to do this differently. Having a trusted messenger is what matters most so we want to make sure we are elevating the good work already happening in that community. That is key.”