Paul Krugman: Trade and Tribulation

Why did Bernie Sanders win a narrow victory in Michigan, when polls showed Hillary Clinton with a huge lead? Nobody really knows, but there’s a lot of speculation that Mr. Sanders may have gained traction by hammering on the evils of trade agreements. Meanwhile, Donald Trump, while directing most of his fire against immigrants, has also been bashing the supposedly unfair trading practices of China and other nations.

So, has the protectionist moment finally arrived? Maybe, maybe not: There are other possible explanations for Michigan, and free-traders have repeatedly cried wolf about protectionist waves that never materialized. Still, this time could be different. And if protectionism really is becoming an important political force, how should reasonable people — economists and others — respond?