I'm sure that's some of the rhetoric well hear, but let's face it...
If John Kennedy hadn't been assasinated, he have most likely been a two term president.
From there, it's no big stretch to believe that Bobby would have run and won in 1968.
In addition, if as you say, the American people aren't too keen on a "familial dynasty"...then why is Hillary tracking so high in the 2004/2008 forecasts.
Once Dubya is successful in executing this war, providing TRUE security to this country and turns the economy around, a back-to-back Bush presidency isn't that hard to swallow...if the American people are convinced of a contination of the "Good Time" under younger brother Jeb.