Donald Trump retreats on Mexico and Canada tariffs again. Also, Trump is criticized globally for turning on Ukraine. Plus, a federal judge rules Trump's firing of a labor board member is illegal. And Democrats hear testimony on the dangers of GOP Medicaid cuts. Amb. Bob Rae, Sen. Jon Ossoff, and Rep. Robin Kelly join Lawrence O'Donnell.

Ontario imposes a 25% tax increase on electricity exports to the U.S. in response to Donald Trump's trade war. Also, Elon Musk attacks Sen. Mark Kelly's visit to Ukraine. Plus, a federal judge partially blocks Trump from defunding USAID. And The New York Times reports a Justice Department official was fired after opposing restoring Mel Gibson's gun rights. Sen. Amy Klobuchar, Sen. Adam Schiff, and Andrew Weissmann join Lawrence O'Donnell.