I am the same height as Obama, and don’t consider myself a height-ist, as my 5’1” mother would call it, but I know it can at times be advantageous.
Only two 20th century Presidents have been 5’ 9” or less: http://en.wikipedia.org/wiki/List_of_heights_of_United_States_presidential_candidates
It’s not that McCain (5'9") can not win because of his height, rather that the height factor will work against him as it relates to perceptions of strength and power when compared side by side with Obama (6'1.5").
Another reason that Obama should accept the invitation to Town Hall Meetings (with the proviso that its not a fixed crowd; http://www.huffingtonpost.com/2008/06/12/mccain-stacks-fox-news-to_n_106881.html) aside from the probability of being able to perform equally or better than McCain, would be to allow the inherent tendency for people to interpret height as power to be demonstrated.
