40% in a large field should be enough. Most contests should be popular vote and winner takes most.
This unity ticket is bad for the independent nature of the general campaign.
Trump shouldnt be forced to cut a deal with Jeb just because he needs another 5 to 9% somewhere. It’s better that the dominant 40% candidate gets in alone.
Trump should not be forced to cut deals with Jeb or Rubio just to get 50% of the vote.
All the congress primaries should have runoffs.
Why should Jeb get any delegates because a voter ticked the OTHER box and he ends up with 5 or 10% of the vote in a state.
If the rules are changed so that the guy with the most delegates wins, then the next time we will have more candidates staying in and the "winner" may very well have support of only 30% of the delegates.
It is only rational that a party nominates someone whom the majority can support.