Olly, I don't think that is entirely fair. Obama is (so far) a unique politician. I can't think of many in recent history, on either side of the Atlantic, that have his broad appeal and sheer flair for soaring, inspiring rhetoric. To me, he is an intellectual liberal who talks about the issues I care about most. I'd wager a fair bet that people with different views to me are also hearing what they wish to hear.
I'm a liberal Tory by inclination, but I honestly believe in Brown's integrity and desire. Ok, he isn't as glam as Obama but so what. Osborne, Cameron, Davis, Cable... (the same) I think we should give them a bit more credit than we currently do.
However, maybe we dont have such rhetorically inspiring politicians in this country because we are collectively more cynical... Can you imagine a UK politician (aside from NI freak religious nuts) making so many references to God? The appeal to transcendence today was pretty remarkable, which says quite a bit about US self image to me.
Think of the appeals to the ideals of the founders of the USA... such powerful mythology. What would we say in the UK? We are collectively embarrased about our Imperial history!
Horses for courses and all that!