ROME — President Biden sought to reverse key policies and approaches of former president Donald Trump during this weekend’s summit of the Group of 20, and attempted to ensure those reversals would stay in place even if there is a change in American leadership.... ...“The United States of America is the most critical part of this entire agenda,” Biden said at a Sunday news conference, responding to a suggestion that the U.S. return to global leadership remains in doubt. “Everyone sought me out...." ...But Biden’s top advisers acknowledged that world leaders approached the talks with a concern that Trump, or...