 would be his premier. A source tells CBS News the Secret Service was aware of a suspicious person with a rangefinder on the ground before the shooting, but did not stop him. President Biden is digging in his heels as he nurses a mild case of COVID amid mounting pressure from Democrats to drop his bid for re-election. Correspondent Ed O'Keefe. The two top congressional leaders, Hakeem Jeffries, Chuck Schumer, and Nancy Pelosi, now have all said to him, essentially,