MILWAUKEE — Gerry Winkleman points across the Milwaukee River at the former tannery where he worked for almost two decades as a union welder, repairing blow pipes and net machines that produced thousands of leather shoes and handbags every year. Follow the latest on Election 2020 Winkleman, 74, drives through a stretch of downtown Milwaukee that once served as a hub of U.S. manufacturing, pausing occasionally to note the factories that have either shuttered or moved their production to China over the past three decades: the Pabst and Schlitz breweries; the Allis-Chalmers manufacturing giant; several different tanneries; the Briggs &...