The Service Employees International Union and billionaire environmentalist Tom Steyer are launching a $10 million effort to turn out voters for presidential hopeful Hillary Clinton and other Democratic candidates in Colorado, Ohio and Pennsylvania, part of a broader effort to expand collaboration between the labor movement and environmental activists.

The new program will involve intense door-knocking and phone banking in working-class communities, with an emphasis on engaging African Americans, Asian Americans and Latinos around the issues of economic inequality and environmental degradation.

“Stopping the Party of Trump is our number one priority this year," Steyer said in a statement. "That’s why our partnership with SEIU is so crucial as we work to empower working families to make their voices are heard this November."

SEIU and Steyer's group NextGen Climate Action will deploy field organizers on the ground in the three states, with plans to expand into others in the coming weeks. They will begin by having conversations with voters about local issues, tailoring their messages to community concerns in order to personalize the stakes of the national election. The goal is to make at least three contacts with each voter before a major get-out-the-vote push in the fall.

"We want the issues to be indigenous to what's going to motivate people to see that particularly this election is going to directly matter in their lives," SEIU International President Mary Kay Henry said in an interview.

The campaign is one piece of a larger political effort by the two million-member labor union, which hopes to get 200,000 members to volunteer in the election.

The joint SEIU-NextGen Climate campaign has its roots in an encounter between Henry and Steyer at a "Fight for 15" protest on the University of California Berkeley campus in 2014. "Ever since then he and I have been trying to figure out, how do we more directly link the economic justice movement with the environmental justice, immigrant justice and racial justice movements?" Henry said.

She noted that the partnership will not end after November: the two groups are discussing ways to maintain a permanent field infrastructure on the ground.

"We are going to try to build neighborhood-based organizations that will keep the fight going post-election," she said.

SEIU's enthusiastic collaboration with Steyer stands in stark contrast to the posture of building trade unions, which viewed Steyer's efforts to halt the Keystone XL Pipeline as a direct threat to the livelihood of their members. A super PAC partnership between Steyer, the AFL-CIO and major public sector employee unions triggered an angry backlash in May, as the presidents of eight building trade organizations called on the AFL-CIO to cut ties with the former hedge fund manager.