On January 20, 2017, Cohn took office as Director of the
National Economic Council (NEC) in President
Donald Trump's administration, a position that did not require Congressional confirmation. By February 11, 2017,
The Wall Street Journal described Cohn as an "economic-policy powerhouse", and
The New York Times called him Trump's "go-to figure on matters related to jobs, business, and growth". With the confirmation of Trump's nominee for
Secretary of Treasury,
Steven Mnuchin, pending in the Senate, Cohn filled in the "personnel vacuum" and pushed "ahead on taxes, infrastructure, financial regulation, and replacing health-care law". Cohn also sold a stake in the
Industrial and Commercial Bank of China, the world's largest bank (), then valued at $16 million. Cohn supports reinstating the
Glass-Steagall legislation, which would separate commercial and investment banking. Under the
Trump administration, Cohn was cited by the press as a supporter of
globalism, and was given nicknames such as "Globalist Gary" and "
Carbon Tax Cohn". He,
Jared Kushner,
Ivanka Trump, and
Dina Powell were referred to by opponents as the "Wall Street wing" of the Trump administration. He was also rivals with trade advisor
Peter Navarro, who favored tariffs and was hawkish towards China; Navarro later described Cohn as "one of the worst and most treacherous misfits of the entire Trump administration". Cohn led the Trump administration's efforts to pass the
Tax Cuts and Jobs Act of 2017. In a 2019 article in
The Wall Street Journal, Cohn pointed to an increase of $6,000 in real disposable personal income per household, as well as the creation of seven million jobs, as evidence of the success of tax reform. Cohn reportedly considered resigning from the National Economic Council after the 2017
Charlottesville rally and criticized the Trump administration's response to the rally, saying, "I believe this administration can and must do better in consistently and unequivocally condemning"
white supremacists. In August 2020,
Jim Sciutto published
The Madman Theory, a book in which Cohn said in response to Trump saying that there were "very fine people on both sides" of the protests which included white supremacists, "Citizens standing up for equality and freedom can never be equated with white supremacists,
neo-Nazis, and the
KKK." By September 2017, the Office of Trade and Manufacturing Policy had been folded into the National Economic Council, which meant that Navarro would report to Cohn. On March 6, 2018, Cohn announced his intention to resign; the announcement followed
Trump's proposal to impose import tariffs on steel and aluminum and Trump's cancellation of a meeting with end users of steel and aluminum that Cohn had arranged in an attempt to dissuade him from the tariffs. He was replaced by
Larry Kudlow on April 2. Cohn's departure solidified the influence of Navarro.
Bob Woodward's 2018 book
Fear: Trump in the White House relates two instances when Cohn removed draft letters from Trump's desk so that Trump would not see them. One of the letters would have canceled a key trade agreement with South Korea, and one would have withdrawn the U.S. unilaterally from the
NAFTA trade agreement with Canada and Mexico. Trump's opinion of Cohn reportedly remained good after he resigned; Trump called him a "rare talent" who had done a "superb job". Cohn supported other candidates during the
2024 Republican Party presidential primaries, but after Trump won the
2024 United States presidential election, Cohn became a "Trump ambassador" to Wall Street for appointments and policy. == Venture capital ==