Seventy years of growing entanglement between science and politics show that the truths that matter most in democratic decision-making emerge from the political arena, not the laboratory. When Democrats sell themselves as the party of science, truth, and rationality, what they are really saying is that if you are rational and believe in science and truth then obviously you will support Democratic policies. But given that half the country does not ideologically align itself with Democrats, this is a hard case to make, and those who disagree with Democratic agendas may in turn wonder why they should accept the science those agendas bring with them. Such skepticism may not be irrational, or even anti-science. Yet it has created a space not just for Trump’s endless effusion of lies, but for the attacks he and his minions are mounting on mainstream scientific knowledge and on the scientific institutions that Democrats had labeled as their own.