The beautiful thing about science is that it works. It doesn’t care if you are a Democrat or a Republican; an atheist, Christian or Muslim; rich or poor. It works. It has consistently provided the tools necessary to improve everyone’s lives. Whether that is to cure disease, to produce the computer or phone you are reading this on, or to heat your home, science works. There have always been two key to foundations that science is built on: scientific data and people. Donald Trump is attacking both of these.

Although we are lumped into categories — biologist, physicist, ecologist — there are very few real silos between fields. Science is a chaotic, swirling mess of ideas that get passed around as we attempt to explain the world. I am a neuroscientist. But, more importantly, I am a scientist. In my field, some of the most influential tools have come from studying how jellyfish glow in the dark and how bacteria survive in salty environments. We take ideas about how magnets align with each other and use them to explain how masses of brain cells are able to work together to perceive the world. I read papers from physicists, from computer scientists, from ecologists and apply this directly to problems of how brains are able to make decisions and communicate with each other.

At the heart of all this is data. Data is not Democrat or Republican, liberal or conservative. Data is. When scientists hear that the Environmental Protection Agency (EPA) is stricken from communicating, that data and studies must be approved by political appointees — no, quick, walk that back, data on the EPA website is being reviewed by political appointees — we don’t hear a focused attack on climate change. We hear an attack on the fundamental basis of science. The EPA does not solely do research on climate change, but funds research on health, on ecosystems, on chemistry, and more. When I scroll through the list of research I see many studies that could help neuroscience and medicine. But how would I know what to trust, what data has been allowed and what has not? An attack on the EPA’s ability to produce data is an attack on all of science.

The more insidious attack on science is on its people. Trump recently announced that visas from certain countries would not be renewable. One of these countries is Iran, one of the largest producers of scientific minds in the world. And they come to the USA! And want to live here and contribute to the scientific enterprise. Because we really do recruit the best minds, and they get here and they want to stay.

There is an important story as to how America became the scientific powerhouse that it is, especially in Physics. Prior to World War 2, the language of science was a mix of French, German and English. But as it became clear that more and more people were unacceptable in Europe, some of the greatest physicists in the world moved to America. Einstein, Bohr, Fermi, Pauli and so many others. And after the war, more and more scientists poured into America: Wernher von Braun led the team that launched America’s first satellite and America’s moon landings. And so, because America took in the best scientists in the world, America became the biggest and best producer of science in the world. And it continues that dominance because this is where the best research is done and it is where people want to be.

But these days other countries do great science, too. What happens to the Iranians who want to come to the U.S. to do a PhD? They can’t anymore. What happens to the Iranians already in the U.S. who wanted to stay here and build their lives here? They left Iran for a reason. But do they want to stay in America anymore? I cannot count the number of times I have already heard from my Iranian friends, “I should have taken the job in Europe.” And it is not just them. Everyone who has a visa is worried about the new fickleness of the system. I have friends from other countries who have lived here for many years who wonder what they are allowed to say, what the likelihood is that their visa might be revoked. Who knows who is next?

One thing is clear: Donald Trump is attacking American science. Donald Trump is attacking the very foundations that science in this country is built on. He is not attacking faceless enemies, he is attacking our very real friends and colleagues. These attacks are so bad that even the most introverted scientists are gearing up to march. This is not about Republicans or Democrats. This is about Donald Trump’s war on science.