This post is part of Polyarchy , an independent blog produced by the political reform program at New America , a Washington think tank devoted to developing new ideas and new voices.

Ten years ago, climate activists were sure they had just the strategy to build cross-partisan political will to tackle climate change. They thought they had amassed enough support from evangelicals, who wanted as much as them to protect God's green earth. That strategy failed. If activists are going to take another run at trans-partisan coalition building on climate, they need to know why.

Today, public opinion on climate science and on the importance of climate action diverges widely along partisan lines, as it did a decade ago when major environmental organizations drew up a legislative strategy that hinged on attracting business and faith leaders to join forces with the environmental movement and build bipartisan support. Environmental funders identified evangelical Christians as a particularly important niche, Lydia Bean and Steve Teles write in a new paper for New America's New Models of Policy Change.

They built a partnership with the Evangelical Environmental Network, a small group that had already worked for years with a bottom-up, theology-before-politics strategy to raise a generation of grassroots leaders who saw response to climate change as part of an authentic evangelical faith.

But the gap between that top-down, short-term strategy and the EEN's bottom-up movement building proved fatal, despite climate supporters' control of the White House, Senate, and House of Representatives.

Advocates called on their evangelical allies to produce public statements from senior figures, and 86 evangelical leaders signed a statement in 2006, provoking major opposition from their own faith partners and political allies. But that very action ignited a counter-movement that continued for several years, culminating in prominent reversals of conservative figures such as Pat Robertson and Lindsey Graham — and then the failure of a legislative effort to tackle climate. Anti–climate change groups successfully urged evangelicals across America to refrain from taking a public position on climate change. Faith-based counter campaigns like Resisting the Green Dragon shattered any illusion of momentum. Some signers disavowed the letter. Others left environmental activism altogether.

How did the coalition fall apart so fast? Bean and Teles argue that advocates and their environmental funders failed to recognize twin threats the creation care movement posed to the Christian right: a) the perceived economic consequences posed a threat to a central player in the conservative coalition, and b) by empowering younger activists less aligned with the conservative movement, it threatened the old guard as arbiters of evangelicalism's political engagement.

Asking evangelicals to take a strong stand on an issue that would divide their base and upset their conservative allies was a recipe for a nasty, divisive fight. Given this, the climate care coalition needed grassroots strength. But though it was tremendously successful at convening champions and opening discussion with new generations, its top-down strategy (focusing on elites that were too removed from every day ministry) did not trickle down, and support from local congregations was not there.

As Greg Sargent writes at the New Republic, the terrain of solid conservative opposition to climate science and policy is shifting. Rand Paul and Jeb Bush affirm from the debate stage that climate change is real. Pope Francis reframes global warming as a moral issue. Graham, who in 2010 reversed his support for climate action to say that climate science was "in question" and had been "oversold," has changed his mind again: "If I went to 10 doctors and nine said, ‘Hey, you're gonna die,' and one says ‘You're fine,' why would I believe the one guy?"

As advocates look for conservative allies for the next climate coalition, three lessons are key: put time into developing relationships and understanding across alliance partners. Take the time to make outsiders full partners in developing and implementing strategy. Give local outreach efforts the time, space, and scale of resources they need to develop. Can the environmental leadership learn a new gospel? That's a question that remains unanswered.