David Wasserman explains why one county could be an early indicator of Trump's election night fortunes

04:50

David Wasserman joins Andrea Mitchell to sort through the latest numbers on early voting, voter registrations, and explain why Sumter County, Florida, could let us know early on if President Trump's re-election bid is in trouble on election night, as it could serve as ground zero for the "gray revolt" that has Joe Biden leading in polls among senior voters - a group Hillary Clinton lost in 2016.