By Julian Zelizer, CNN Contributor
Editor's note: Julian Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter" and of the new book "Governing America."
(CNN) - Election night could be a long one. Many of the polls continue to show a tight race with the candidates remaining in a dead heat in the swing states. Whoever wins the election, it might not be by much.
Close elections have produced challenges for the victor once he starts his term in the White House. If voters don't provide a clear mandate, presidents often find that they have added challenges when dealing with Congress, as legislators have far less fear about the commander in chief.FULL STORY