Canadian Foreign Minister Chrystia Freeland was back in Washington on Tuesday, rejoining NAFTA negotiations with U.S. Trade Representative Robert Lighthizer after weeks on the sidelines. The United States and Mexico have sketched out the beginnings of an agreement, and the question now is whether Canada can be brought into the deal. On Monday, President Donald Trump seemed ready to move ahead with a U.S.-Mexico agreement absent a timely deal with Canada. That would complicate businesses and supply chains, for sure. It might also not work legislatively, thanks to something called Trade Promotion Authority.

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