Chomsky et al argue (convincingly to me) that the US is effectively an oligarchy (as defined in the clip - not according to the original Greek etymology -
). Whilst the intention may have been a constitutional republic (and there is no doubt that the original constitution discriminated against women, slaves etc), the reality today is an oligarchy (or as the vid says - a tyranny of the elite).
Chomsky argues that the President can only come from a very selective set of people who are defined by the views/policies that they will enact. The nomination process just dresses up an oligarchy as a democracy or as a republic (as this video argues).
In practice, the electorate does not have a free choice of the candidate that they would choose - but have to effectively choose between the choices made for them - by those who do have real power. No, not necessarily zionists - but rather those with vested interests who control big business, media etc - not necessarily WASPS, just the monied classes.
That said, the vid is interesting for the historical insights - and certainly I agree that the founding fathers did not envisage a democracy as defined (but the US did end up with an oligarchy).
Cheers,
Shafique