Republican Sen. Mitch McConnell is speaking out against President Donald Trump’s sweeping tariff plans, warning that starting trade wars with U.S. economic partners could force higher costs on American families and businesses. Trump’s “aggressive proposals leave big, lingering concerns for American industry and workers,” the senator from Kentucky wrote in an op-ed Wednesday in Louisville’s Courier-Journal. The op-ed is a rare example of a senior Republican in Congress who is willing to publicly criticize the president’s economic strategy. Trump, who has called tariff his “favorite word,” recently slapped broad import duties on Canada, Mexico and China, plus additional tariffs on...