President Donald Trump returned to the White House in January determined to overturn decades of American policy and build a tariff wall around a U.S. economy that used to be pretty much wide open to foreign products.

WEST MIFFLIN, Pa. — President Donald Trump on Friday told Pennsylvania steelworkers he’s doubling the tariff on steel imports to 50% to protect their industry, a dramatic increase that could further push up prices for a metal used to make housing, autos and other goods.