“I’m not comfortable with letters anymore,” said Patrick Cronin, head of the Asia-Pacific security program at the Hudson Institute, who signed the first letter, which called Trump “fundamentally dishonest” and “utterly unfitted to the office.” In March 2017, Cronin was forced to withdraw from a new position overseeing a Pentagon think tank after Trump allies blasted his appointment by then-Defense Secretary Jim Mattis.

“I don’t regret the letter in 2016; I thought it was the right thing to do,” said Cronin, who has been publicly supportive of some elements of Trump’s policies on China and North Korea. “But I’m not writing or signing any letters in 2020. I’m not predicting the outcome of the election. I will be supporting the U.S. government.”

Of the 149 experts who signed at least one of the two letters warning that Trump was unfit for office – the first published on the War on the Rocks website during the 2016 GOP primaries and the second on the New York Times’s site during the general election campaign – just one has been hired by the Trump administration. James Jeffrey, a Middle East expert who served under Presidents George W. Bush and Barack Obama, was named the State Department’s special representative for Syria last summer, before adding the role of special envoy to counter the Islamic State in January.