Trump threatened to impose a 35 percent tariff on Canadian goods beginning Aug. 1 unless Canada decides to build or manufacture its products in the U.S. The letter to Carney was part of the administration’s fresh blitz to secure trade deals after postponing the original July 9 deadline to reinstate the tariffs first announced in April.

MSNBC's Lawrence O'Donnell and Jen Psaki discuss the breaking news that Donald Trump is now threatening Canada with tariffs of 35% claiming the "flow of fentanyl" from America's northern neighbor as his reason.