Particular the Clintons and the Bushes. If Hillary Clinton wins in 2008 (I would say that is a good possibility) and goes two terms … and then she is followed by Jeb Bush for two terms (another possibility) …
In every presidential election from 1980 - 2020 (or 32 yrs), either a Clinton or a Bush will have been on the winning the presidential ticket. That makes us look like a development nation with a struggling democracy.
Do we really want presidential politics dominated by just a few families? This isn’t to say that a member of a family dynasty can't be a good President. It is only to be very wary of concentrated power.
Our founding fathers were very concerned about dynasties. It isn’t coincidence that out of our first five Presidents, only Adams had a son. And Adams was very telling. He was the only one of the first five Presidents to last only one term and, to prove the power of dynasties, his son, John Quincy Adams, became the sixth President.