 It's Morning Edition from NPR News. I'm A. Martinez in Los Angeles, California. And I'm Michelle Martin in Washington, D.C. Good morning. President Biden is fighting off COVID and the growing number of calls for him to withdraw from the presidential race. John Tester of Montana has become the second Senate Democrat to go public with a call for Biden to step aside. California's Adam Schiff, who is running for the Senate, heads the list of 22 House Democrats who are also openly calling for the president to withdraw.