This is a joint post with Andrew Cheon, a PhD Candidate in Political Science at Columbia University. Cheon and Urpelainen are working on a book on activism against fossil fuels and joined the People’s Climate March both as concerned citizens and academic researchers.

On September 21, hundreds of thousands joined the People’s Climate March (PCM) in New York City. While the marchers were a diverse group, it was diversity among liberals and leftists. The anti-globalization, anti-corporate, anti-agribusiness, socialist, and labor activists were all there in large numbers, making a lot of noise.

Even among the large number of ordinary New Yorkers who joined the march, liberal political views were strong. We did some short surveys of a random sample of participants to understand why they joined the march. We’re still processing the data, but it’s already obvious that almost everyone from the march identifies with the political left. So far, we have yet to see a single marcher who identifies with the political right.

The leftist bias of the PCM is not surprising. Most activists against climate change are liberals and progressives. Conservatives in the United States often associate climate activism with the liberal agenda. While climate change need not be a political issue, in practice it’s a much higher priority to left-wing than to right-wing activists.

But is the leftist bias a problem? Some commentators seem to believe so. According to Sieren Ernst, the PCM could have reached conservatives with more cautious messaging and steering clear of the anti-corporate message. Ernst disagrees with Grist’s David Roberts, who earlier wrote that the PCM cannot change climate politics in America because conservatives are beyond the reach of the organizers.

This disagreement is at the heart of the matter. If the PCM could have mobilized masses of conservatives to demand climate action, then it’s pretty clear that the organizers should have focused their messaging and framing to create a broad base that includes both the political right and the left. That would have been a huge breakthrough in climate politics.

Unfortunately, it’s not that simple. For one, even if Ernst is correct that there are many conservatives who are now concerned about climate change, it doesn’t mean that they are willing to head to New York to organize a march.

The organization of the march was a huge effort – endless meetings and working groups over at least a year – and the people who contributed were passionate activists. These are not people who just worry about climate change. These are people for whom activism is a lifestyle, a passion, and an obsession.

Any serious effort to reach out to conservatives would have required an extensive network of conservative activists willing to dedicate at least a year of their lives to the march. How many conservatives consider climate change such a top priority? There’s a world of difference between accepting the science and devoting countless hours to grassroots activism for a cause.

The second problem is that the organizers of the march are dependent on the people who show up. If an anti-globalization group shows up and contributes time and money to organize the group, what can the organizers do? In some of the organizing events we attended, there were hundreds of groups present. If the organizers had started discriminating against participants based on their political views – with the obvious exception of, say, hate groups – the whole effort might have collapsed.

Inclusiveness is both the strength and weakness of grassroots activism. Almost everyone’s welcome, and there is no centralized planning committee to decide who can join the march. This means that vocal fringe groups participate. Nobody can stop them.

So, the debate about the PCM and conservatives is largely hypothetical. Everyone agrees that we need more conservative climate activists, but the PCM, by its very nature, was not a great mechanism for reaching conservatives. The PCM achieved its goal of mobilizing liberals and progressives to demand climate action, greatly increasing the salience of climate change in the United States. Given that the PCM was organized by thousands and thousands of passionate liberals and progressives, all with diverse goals and perspectives on climate change and other social issues, their ability to really connect with conservatives was limited.

We absolutely need people who can talk climate science to conservatives, such as the self-identified evangelical and top climate scientist Katharine Hayhoe. In her column, Ernst also notes that climate groups such as Citizens’ Climate Lobby are demanding climate action without a liberal or conservative bias. The Energy and Enterprise Initiative at George Mason University, which offers explicitly conservative approaches to climate policy, is another notable effort to promote climate change mitigation from a conservative perspective.

However, it’s wishful thinking that and their allies could play this role. If the PCM organizers had tried to reach out to conservatives, they might have alienated their own supporters without convincing conservatives. A staunch conservative probably does not want to hear what Naomi Klein or Bill McKibben has to say about climate change or the future of the American economy.

To end this post on a positive note, we should not forget that radical activism on the liberal side of the political spectrum may itself even contribute to the success of moderate conservatives. If liberal activists are loud and visible, they may actually enhance the political clout of moderate conservative climate activists. In the academic literature, this is called the “radical flank effect” (gated content). For example, Martin Luther King was considered a radical by many until Malcolm X and the Black Panthers showed up. The existence of a radical alternative may make a moderate climate activist more acceptable to the public.