Editor's Note: This article is one of 50 in a series about Trump's first two years as president.

Since 1976, the president of the United States has relied on a science adviser—a kind of nerdy consigliere—to offer counsel on nuclear disasters, disease outbreaks, emerging technologies, changing climates, and more. That position, formally the director of the Office of Science and Technology Policy, is as close as the scientific world gets to a Cabinet-level role. But under Donald Trump, it sat fallow for a uniquely long time. Many previous presidents nominated a science adviser before they were even inaugurated. George W. Bush did so five months after taking office—then a record-breaking delay. Trump waited 19 months.

During that lengthy lull, he could have turned to other scientific agencies for advice, had he not populated them with candidates who were unqualified or opposed to the organization they were meant to lead. For his Environmental Protection Agency administrator, Trump picked Scott Pruitt, a man who had repeatedly sued the agency. He selected Rick Perry to head the Department of Energy, which Perry once pledged to abolish. Sam Clovis, a former Air Force officer and talk-show host without any scientific background, was Trump’s pick for chief scientist at the Department of Agriculture. Brenda Fitzgerald, his choice to direct the Centers for Disease Control and Prevention, was forced to resign after reporters revealed that she had bought tobacco-company shares. In making these picks, Trump showed such little regard for scientific expertise that when he finally nominated a science adviser with actual scientific credentials, the respected meteorologist Kelvin Droegemeier, it came as a surprise.

Droegemeier may not be able to  temper Trump’s negative posturing toward scientific evidence—his attitude has ranged from casual disregard to outright antipathy. During his 19-month stint without a science adviser, his administration pulled out of the Paris Agreement on climate change, reversed or postponed a number of environmental regulations, and attempted to significantly slash the budget of many scientific agencies in two successive budget proposals.

His administration has also pushed forward several policy rules and bills that are ostensibly designed to bolster transparency and rigor in the way science is used to inform policy, but that in practice would prevent agencies from even considering significant swaths of research or placing qualified scientists on advisory boards. These moves go way beyond the common practice of cherry-picking evidence, and instead discard that evidence entirely. They send a message: In this administration, empiricism is inconvenient and expertise unnecessary.

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