Nonsense. Please explain how Bush/Rubio would be winning if they were running in the Dem system, and relate that winning to party bosses.
edit: Jeb Bush, who was routinely receiving 3% in the polls and at the ballot box, would somehow be winning. Jeb Bush.
I suspect Trump may have not entered to begin with if he knew that 20% of the delegates would not vote for him, and that plurality victories didn't get disproportionate wins.
Also, many of the superdelegates on the Democratic side are the local party heads and folks who wield immense local power. They could organize the local parties to go after Trump and Cruz, in terms of spending money and canvassing, etc etc. Jebis probably too weak of a candidate (except for fundraising, dear lord), but Rubio or Kasich may have gathered a stronger base to start from and would have a much stronger case at a contested convention.
Also - the GOP primary process, having multiple winner take all states and winner take most states - led itself wide open to a candidate winning ~44% of the delegates with 34% of the votes. Something that can't happen on the Dem side due to pure proportionality.
http://fivethirtyeight.com/features/donald-trump-would-be-easy-to-stop-under-democratic-rules/
Because of GOP rules, candidates are incentivized to act state by state rather than on a national basis, and that was a big reason it took so long for the GOP to realize they needed to gang up on Trump. Every candidate was thinking "I can try to win this state, and let everyone else beat up on Trump and Cruz".
How do you figure that? Superdelegates? How would Trump not be as far ahead as Clinton is?
To me, the Dem primary system is showing that an early lead is basically impossible to overcome but if you can convince people to keep giving you money then it doesn't matter.
Superdelegates + pure proportionality. See the 538 article linked above.
Dem primary incentivizes GOTV (Caucusing) and national policy debate (pure proportional delegates) along with being a little cynical about populism as well as an eye on establishment types (high % of super delegates to stop any Trump like figure as well as empower local / national party leaders rather than pure voters).