Political Dynasties; Bushes and Kennedys

[fencesitter]

A story on NPR about the Bush family dynasty this morning got me thinking. Given the founding of America was about a break from monastic rule and power based on lieage, why is this never an issue with family dynasties like Bushes and Kennedys? I may be naive and ill-informed, but the difference between the two is the Kennedys seem to have a calling to public service, to serve the people, whereas the Bush family is all about the consolidation of power. I have always felt the elected Kennedys are looking out for the citizen as opposed to the alternative.
So how is it the Kennedy family has this stigma and reputation as elite, out of touch, wealthy northeastern liberals,(which they are, wealthy NE liberals anyway) but the Bush family is somehow percieved as down home, humble good old boys that you could hang around a bar with? (which they most absolutely are not.) If I was an average conservative working class citizen I would be very suspicious and distrusting about electing such a politically connected dynasty into power and how would I think they have my interests at heart? Go figure.