President Trump has tapped television and radio personality Larry Kudlow to lead the National Economic Council, as his top economic adviser.

The nomination comes days after Gary Cohn, the NEC’s former head, stepped down citing differences with the president over a new trade policy that includes imposing heavy tariffs on foreign aluminum and steel.

Kudlow, a commentator for CNBC known for his conservative politics, informally advised Trump on economic matters during his presidential campaign, and also consulted with Treasury Secretary Steve Mnuchin, as he helped Congress draft the recent overhaul of the U.S. tax system.

Originally a Democrat, Kudlow switched parties and later served President Ronald Reagan as an economic adviser in the 1980s, according to reports. He is a supply-side economist, meaning he believes that lowering taxes on corporations and the wealthy will increase investment in business and the economy.

What’s the NEC?

The NEC helps to coordinate policy-making for domestic and international economic issues. It also helps to coordinate economic policy, advice, and goals for the president, and assists in  implementing the president’s economic policy agenda, according to its mission statement.

Kudlow, a commentator for CNBC known for his conservative politics, informally advised Trump on economic matters during his presidential campaign

One objective of the NEC is to ensure the president hears competing points of view on economic policy.

Disagreement over tariffs

Kudlow has agreed with Trump on tax cuts and deregulation, but has differed with the president over tariffs.

“Steel and aluminum may win in the short term, but steel and aluminum users and consumers will lose,” Kudlow wrote recently in an opinion piece on CNBC, adding that “tariff hikes are really tax hikes” that may jeopardize 5 million manufacturing jobs in the U.S.

Trump had also considered Christopher Liddell, a former executive at both General Motors and Microsoft, as well as Peter Navarro, another economic adviser to the president who pushed for the tariffs, according to reports.