A little perspective: How well do front-running outsiders do once the voting starts?

How have front-running political outsiders fared in previous presidential primaries?  Not well (at least for the past two presidential campaigns), according to this feature from the Wall Street Journal, which analyzes trends from 2008 and 2012 nationally and in Iowa and New Hampshire. 

Will that pattern continue during this year's contests?  A good question to discuss with your students.