US elections

I am surprised at the number of people I know, and who I think of as political, who are getting excited at the prospect of the election of the first black Presidet of the USA. I can't help thinking that the idea that this would be an historic victory involves a very shallow idea of history. I keep thinking 'what did Margaret Thatcher's premiership do for women?', 'what did Nelson Mandela's do for most black South Africans?'. The excitement seems to me to be part of a shift in understanding of representation from representation of interests to representation as presentation. The 'triumph' of appearance over substance (or perhaps more correctly the eclipsing of substance by appearance). What I find difficult to understand is why appearance excites people in a way that substance doesn't? I can understand that appearance has more appeal when substance (or substantial differences between candidates) is lacking. But when people talk about high turnouts, reengagement in politics, excitement about politics, why is this? Is there actually more excitement about this election than the election of JFK or Nixon? If so, what does this excitement consist of?