Free trade has taken a beating on the campaign trail this year. Donald Trump, Bernie Sanders, and Hillary Clinton all have taken shots at the impact of trade on the American economy.

That disturbs Scott Lincicome, an international trade attorney who serves as a visiting lecturer at Duke University and adjunct scholar at the libertarian Cato Institute. Lincicome touted the benefits of trade during a speech at the John Locke Foundation marking Friedman Legacy Day. That’s the day each year reminding people about the work of Nobel Prize-winning economist and free-trade advocate Milton Friedman.

In the video clip below, Lincicome urges fellow free traders to emulate Friedman’s example.

6 p.m. update: Click play below to watch the full presentation.