Election officials from across the country met in St. Louis for the National Election Security Summit. It's a last chance to meet together, and with Homeland Security, before the midterms to learn about the latest cyberthreats. DHS Secretary Kirstjen Nielsen told election administrators Monday that while "real progress" has been made in election security, "to be frank, a great deal of work remains." Chief National Investigative Correspondent Mark Albert reports from the summit.