On Saturday, hundreds of thousands of people are expected to march in Washington, DC, to celebrate and defend science—at a time when many believe that science does, in fact, need defending. President Trump’s budget proposal cuts 31 percent from the Environmental Protection Agency, slashes the Department of Energy’s basic science research program, and zeroes out a program that supports early-stage research into technologies that can reduce our national dependence on fossil fuels. The National Institutes of Health (NIH), which spends $32 billion a year on biomedical research — most of which is undertaken in labs at universities and medical schools across the nation — would see a 20 percent cut, bringing the agency’s budget to its lowest level in 15 years. Beyond science, the president’s proposed budget also eliminates the National Endowment for the Arts and the National Endowment for the Humanities.