Simon Lester, at Cato at Liberty, has a telling Twitter discussion with Dan DiMicco of Nucor Steel. DiMicco is an adviser to president candidate Donald Trump. According to Time:

He [DiMicco] has been an avid supporter of Trump’s trade proposals, recently writing, “The Trump trade policy is both sound and necessary in today’s World where ‘Trade Cheating’ has become the norm.” DiMicco became Trump’s trade advisor in early July, saying he had never met Trump in person but had corresponded with him for a decade.

In other words, if Time has identified DiMicco’s role accurately–and it may not have–DiMicco is not just an adviser to Trump but an adviser on trade. So, again assuming Time is accurate, you would expect him to know Trump’s views on trade and also understand, if not the economics of international trade, at least the current laws on trade.

At least that’s what Simon Lester expected. But in a civil exchange with DiMicco, Lester found out that DiMicco doesn’t understand NAFTA.

Read it for yourself.

Here’s Lester’s bottom line:

A conversation like this leaves you very puzzled. Trump says he wants to renegotiate NAFTA. Yet neither he nor his advisers can explain what they want to change. It’s not a hard question. I can think of quite a few things I’d change about NAFTA! No trade agreement is perfect. My main take away is this: When Trump’s trade advisers are unable to explain the basic details of Trump’s trade policy, it’s no wonder that Trump sounds so uninformed and incoherent when he talks about trade.