Honestly, history is no benchmark, thanks to the 'Peculiar institution' of Superdelegates. The actual effect of this bizarre bit of antidemocratic chicanery is to leave the decisive balance in question if there is a contender who is carrying a large minority of states. It really could result in Bernie being the nominee, if he stays in until the bitter end and in the unlikely event that Hitlery ends up indicted on felony charges before the DemonRat convention. Her commanding lead relies on delegates that have made a (Completely reversible) pledge to support her, but are in fact legally obligated to do so and can turn on her like an Italian government.