Peter Thiel, a venture capitalist and biomedical research investor who is one of Mr. Trump’s few supporters in Silicon Valley, is an outspoken advocate for government-fostered science. A week before the election, he said: “Voters are tired of hearing conservative politicians say that government never works. They know the government wasn’t always this broken. The Manhattan Project, the Interstate Highway System, and the Apollo program — whatever you think of these ventures, you cannot doubt the competence of the government that got them done. But we have fallen very far from that standard, and we cannot let free market ideology serve as an excuse for decline.”

That, however, is exactly what Mr. Trump’s budget does. In service to small-government ideology, it proposes to whack 18 percent from the N.I.H.’s budget, and even more from the Department of Energy and the E.P.A.’s science programs. A $250 million annual grant program administered by the National Oceanic and Atmospheric Administration “supporting coastal and marine management, research and education” would be killed, including programs that provide important resources to help coastal states prepare for the coming effects of climate change (no surprise there, since Mr. Trump doesn’t believe in climate change). The earth sciences division at NASA comes in for a 6 percent cut; other reductions take aim at the United States Geological Survey and the National Science Foundation, a big player in scientific research.

The cuts in human health programs have drawn the heaviest criticism. Mary Woolley, president of Research!America, nonprofit advocates for medical research, says Mr. Trump’s budget “doesn’t reflect the priorities of a nation committed to protecting and improving the health and well-being of its citizens.” The N.I.H.’s 27 institutes underwrite the bulk of the nation’s medical research; after hefty budget increases in the early 2000s, championed by Senator Arlen Specter, who was a Pennsylvania Republican, the economic downturn and internal turmoil have led to cuts that erased most of those gains.

Mr. Trump’s budget greatly worries medical researchers like Dr. Jeffrey Lieberman, chairman of the psychiatry department at Columbia University College of Physicians and Surgeons and director of the New York State Psychiatric Institute. Nearly 60 percent of Dr. Lieberman’s $240 million departmental budget is sponsored research, most of it underwritten by the N.I.H. “Each year we eat what we kill — there is no guaranteed recurrent revenue,” he said. “And this is true for all academic medicine.”