Three Democratic senators are alarmed by reports that the U.S. could “back down” and accept a minor trade arrangement with China when President Trump and his Chinese counterpart meet in Argentina on Saturday. Senate Minority Leader Chuck Schumer (NY), along with Sens. Ron Wyden (OR), the ranking member of the Finance Committee, and Sherrod Brown (OH), told Trump in a Nov. 28 letter that he should stay firm when he meets with President Xi Jinping on Saturday at the G20...