Imbecile president uses Twitter to start trade war with third-largest trading partner because he’s a racist idiot
By 
President Donald Trump threatened on Thursday to impose new tariffs
on Mexico if the country does not step up its immigration enforcement actions, combining his boiling border-related frustrations with his preferred method of punishing foreign countries.
Trump said in a White House statement that the first round of tariffs would begin on June 10 at 5% “on all goods imported from Mexico.”
The statement said Trump would carry out his threat under authority from the International Emergency Economic Powers Act and that he would lift tariffs only “if the illegal migration crisis is alleviated through effective actions taken by Mexico.”
The statement warned further that if Mexico does not act as Trump demands, tariffs would go up to 10% by July, 15% by August, 20% by September and reach a permanent level of 25% by October.
The silver lining is that this will cost some rich people a few dollars, thus inflicting approximately infinitely more political damage on Trump than murdering some more kids at the border.
ETA: Yglesias explains there’s an easy off ramp here, which is that migration from/through Mexico is very seasonal, peaking in the spring and declining sharply in the summer. So Trump could always get or pretend to get some “concessions” from Mexico and declare victory in a couple of months. That would be the smart move, relatively speaking, because his moron supporters would surely fall for it. But “smart” and “Trump” go together about as well as avocado toast and circus peanuts, so don’t count on it or anything.