St. Louis (KSDK) - Millions watched Wednesday night, and many are still talking about the first presidential debate.
Some might say the most important person in this year's election isn't either one of the candidates.
PHOTOS: First presidential debate
Instead, it might be the undecided voter.
So who exactly are the undecided and how do they campaigns find them?
Harry Smith from NBC's Rock Center joined us live from New York to talk about it.