Why doesn’t practice make perfect? Why are the same mistakes replayed in every presidential election? Political scientist Samuel Popkin looks at three campaigns – George H.W. Bush’s muddled 1992 re-election effort, Al Gore’s flawed 2000 campaign, and Hillary Clinton’s mismanaged effort to win the 2008 Democratic nomination – and uncovers lessons that future candidates should heed.

Popkin is a professor of political science at the University of California - San Diego.