BOSTON — Scientists have long spoken up for causes like the proliferation of nuclear weapons and climate change. But with President Donald Trump in office, something’s different.

On Sunday, hundreds of scientists filled Boston’s Copley Square at a rally, holding signs with statements like “Alternative facts are the square root of negative one.” Thousands are expected to show up at the March for Science in Washington, planned for April 22.

“When the proposed budget comes out ... it’s going to be a horrifying but unifying document”

More scientists are mobilized and excited to speak up for their field than ever before. What’s new is that they’re organizing — from the grassroots up — under the broad banner of science.

But like a lot of groups clamoring to counter a new administration that’s hostile to their issues, scientists now have to figure out how to direct their energy. And that’s not easy.

What’s a scientist to do in the age of “alternative facts”?

In 2015, the Pew Research Center compared public opinion on science issues with a poll of members of the American Association for the Advancement of Science. Pew found that while the public still has a largely positive outlook of scientific institutions, there’s a gulf between what scientists believe about scientific topics crucial for policy and what the public believes. Regardless of how the public feels about scientists, some of their messages aren’t getting through.

Some scientists have taken this to mean that scientists need to get better at communication. “Now is the time for a quantum leap into relevance,” Jane Lubchenco, a former NOAA administrator under Obama, said at a roundtable discussion on Saturday in Boston at the AAAS’s annual meeting. “We need to do a lot better job at demonstration, not just asserting, the relevance and importance of science.”

But stating facts alone isn’t enough to win a debate. For instance, work by psychologist Dan Kahan shows that increasing scientific knowledge only further polarizes people on hot-button topics. (To my ear, this was the most cited bit of research at the conference.) It’s a flaw built deeply into the human brain: When we have to choose between accepting facts and protecting our social groups, we protect our social groups.

At the AAAS meeting, Kahan said that scientists need to be wary of creating “toxic memes,” which are stories framed in a way that is sure to create partisan divides. (For example: Stories linking the Zika virus to immigration polarized liberals and conservatives over whether Zika was a threat to the United States.)

Naomi Oreskes, a Harvard historian of science, implored colleagues at the conference to think beyond cold, hard facts and start considering telling science stories with narrative and emotion. She said that scientists often equate emotion with simplemindedness. “Get over it,” she said.

Strategies for effective science communication were abundant. Asheley Landrum, a psychologist at the University of Pennsylvania, presented evidence that suggested that stoking people’s curiosity can be a means to bridge a partisan divide. Joanna Huxster of Bucknell University explained people seem to be more accepting of science when they better understand the scientific process. Sara Brownell at Arizona State University talked about how it’s easier to teach evolution to skeptics when teachers are more empathetic about religious students’ concerns.

This is all important work. More people in America should interact with scientists, and scientists should work to earn the public’s trust. But it’s policymakers who make some of the most impactful decisions on these issues. How can science motivate them?

Scientists’ problem may not be scientific illiteracy. It may be Donald Trump, Republicans in Congress, and their policies.

Scientists are worried about the deregulation of the Environmental Protection Agency. They’re worried that President Trump has a pattern of being swayed by anti-science views, like the thoroughly debunked link between vaccines and autism. They’re particularly worried that the Republican Congress — keen to lower taxes while increasing spending on defense and infrastructure — will cut science funding to balance the books. And many of them are now eager to learn how to confront these threats.

“Donald Trump is going to be the gateway drug for scientists being engaged in policy,” said Gretchen Goldman, the research director for the Center for Science and Democracy at the Union of Concerned Scientists.

Scientists have long been active in Washington, putting pressure on Congress and advocating for funding for their work. Groups like AAAS and the American Geophysical Union do a lot of this work. But many scientists are new to the world of political advocacy and have a lot to learn.

“When the proposed budget comes out,” said Kenneth Kimmell, the president of the Union of Concerned Scientists, “it’s going to be a horrifying but unifying document, and you’re going to see large elements of civil society rise up in a unified manner, and that will lay the groundwork for what should happen next.”

Scientists will have to confront the fact that elections matter

In the midst of newly mobilized scientists in Boston over the weekend, I felt one topic was largely avoided: elections.

In the coming years, scientists may discover that public engagement, obstruction, and civil disobedience won’t enough to combat Trump. They may discover that they’ll have to be more directly political, and help candidates who explicitly back science get elected instead of candidates who scorn it.

The Union of Concerned Scientists doesn’t advocate for individual candidates. None of the major science advocacy groups in the US do. The upcoming March for Science organizers say they’re not inviting any politicians to speak, nor will they endorse any.

Their chants ricocheted off the walls of the neighboring Boston Public Library, not Mar-a-Lago

But if scientists really do want to effect change, I wonder if they’ll be tempted to refocus their message on who we put in office. Consider how swiftly the country changed in one single day: the day Trump was elected president.

Obama science adviser John Holdren — who was sort of a walking, talking representation of all the science community lost in the transition to Tump — warned that if members of the science community wanted to make changes, they’re going to have to focus. “If we let a thousand flowers bloom, which may well happen, one liability is that we may end up with a whole that’s less than the sum of its parts,“ he said. “We need to be strategic … to figure out collectively where the leverage is.” (He didn’t explicitly say that leverage is electoral.)

But it’s a fair point. The awakening of scientists as a political identity has to be focused on some political pressure point to make change.

At the rally, most of the speakers stressed that they in no way want to make science partisan or political. They instead want to make a show of solidarity for their way of thinking and institutions. “We didn’t politicize our science. We did not start this fight. [It was started] by people who are motivated to reject facts.” Oreskes said. (Complicating matters: There are scientists who greatly fear that rallies will be counterproductive, and perhaps become a “toxic meme” welding science to liberal partisan politics.)

A rally in the heart of Boston — arguably the most science-friendly city in the country — isn’t going to, in the words of many of the demonstrators, “restore science in its rightful place.” Their chants ricocheted off the walls of the neighboring Boston Public Library, not Mar-a-Lago.

But the rally showed something important. It showed that “scientist” or “science advocate” is a political identity that can be further activated and mobilized.

“I think we all certainly think [future] political work is crucial, but I also think many of us feel we have to first make the case why we, as scientists, are taking to the streets, since that is not something scientists normally do,” Oreskes said.

To be effective, they’ll definitely have to figure out a clear answer.