text:  On Sunday, four more senior House Democrats on a private call told their leaders they want a change at the top of the ticket. Senate Democrats have not made any public appeals yet, but will discuss the path forward this week. Connecticut Senator Chris Murphy said on CNN the president needs to show he's up to the job. I take him at his word. I believe that he can do it, but I think that this is a really critical week. I do think the clock is ticking. The president insists he's not going anywhere. Deirdre Walsh, NPR News.