November’s presidential election may seem like its still very much up for grabs, but journalists and pundits are already making their picks and predictions — and they often rely on conventional wisdom. For example, "incumbents always lose if unemployment goes above 9 percent in the days before the election." But conventional wisdom only tells us part of the story. What candidates do and don’t do on the campaign trail, and whether they are the incumbent or challenger are also key factors. Join Diane for an examination of what it takes to win the White House, and what previous campaigns can tell us about the one we are watching unfold.