A group of top business leaders is ratcheting up pressure on President Joe Biden to drop his re-election bid in a letter signed by 168 people, including Christy Walton, Michael Novogratz and Paul Tagliabue, according to a copy of the Leadership Now Project letter. It is unclear how much influence top Democratic gifters will ultimately have on Mr. Biden's decision. He reportedly relies on a small circle of trusted members, including his wife Jill and son Hunter.