This would be incredibly ineffective because we would end up without a
majority nomination. While a blatant majority of the populace might not want $Repub or $Democ, their
collective nomination of
one third party president is unlikely at best. Some would vote for the extreme left, some for an extreme
conservative, some
libertarian, etc. While this works in a
parliamentary system, it would fail horribly when used to elect a singular
figurehead. The
President would lack popular support and would certainly not be able to work with the
congress. It's a great concept, but like so many others it can't really be applied to the American political machine.
Embers: True, they did have that. They even had candidates who weren't Communists. Oddly enough, few people voted for them, and often those same people ran intro problems finding jobs down the road.
Artfuldodger: While the current president may not have popular 'support,' as in the majority of the people standing behind his actions, he does have minority support and popular apathy. I doubt that this is a good thing, however it appears to work at least to some extent. The real beef I have with "None of the above" is that it implies absolute cluelessness as to who the leader should be. As I stated before, those people who select "None of the above" will belong to many factions and any one of their individual leaders will bring forth violent opposition by the other factions as well as the mainstream, making the position less than productive.
Artfuldodger: True, possibly it should grind to a halt. However, do you expect it to present the people with that option? It seems more reasonable that the status quo gov't would do all it can to keep any dissidents out of power and maintain the appearance of a supportive public.