Burnham made two unsuccessful bids to become Labour leader. Are you suggesting all those who voted for other candidates are narrow minded?
They were in case you forgot the other candidates were -
2010 - Ed Miliband, David Miliband, Ed Balls and Diane Abbott
2015 - Jeremy Corbyn, Yvette Cooper, Liz Kendall
It may be an alien concept but it's democracy. The definition of narrow minded is not "someone who disagrees with you"