President Trump has promised or threatened, depending on one’s perspective, to renegotiate NAFTA. However, most U.S. ag groups have communicated their reservations about doing so. Meanwhile, one Mexican senator has responded with a proposal that could impact U.S. corn.President Trump has promised or threatened, depending on one’s perspective, to renegotiate NAFTA. During the 2016 campaign, he famously called it the “worst trade deal ever” and has directed most of his ire at Mexico. After meeting with Canadian Prime Minister Justin Trudeau yesterday, Trump remarked about trade relations with Canada under NAFTA, “It's a much less severe situation than what's taking place on the southern border." The root of his concern is that Mexico, like ma...