 There are a lot of lingering concerns, Alex. We can't put on a happy face. There are very honest and serious and rigorous conversations taking place at every level of our party. Top Biden officials still haven't explained why Biden seemed to struggle the way he did on Thursday. But they tell CBS News they are staying the course. Nothing has changed. We are full steam ahead, one said. We still believe Biden is the best position to beat Trump. They point to his energetic post-debate campaign stops.