Iin the weeks After Donald Trump’s landslide election victory, U.S. companies sought to reassure investors that they were fully prepared for a new series of prices. Some, like Stanley Black & Decker, a tool maker, have highlighted efforts to shift their supply chains away from China. Others, like Lowe’s, a home improvement retailer, pointed to the processes they put in place to handle tariffs after Mr. Trump’s first term, during which taxes were imposed on about $380 billion. of dollars in imports ranging from steel and aluminum to washing machines. , mainly from China.