I do believe that the story will be told after April 26th.  At that point, it will most likely be nearly impossible for either leader to get the 1237 delegates needed for an outright win.  At that point, it will be clear that it's going to be a contested convention.  The date could possibly slip to May 10th or May 17th, but I don't think that it will go that far.

 

What will be really telling is what Trump does at that point.  Will he drop out and announce that he is running as an independent, or will he stick in there all the way up to the convention?  My guess is the former, and by design.  He wants to siphon off the republican vote in the general election.  By that point Hillary will have sewn up the democrat coronation nomination.  It will be interesting to see what Bernie Sanders supporters do at that point as well as what the socialist himself does.  Does he also try to run on an independent ticket as well?  Probably not.  If he does, then it could make for an interesting general election.  Trumpettes siphon off of the republican side while the "feel the bern" sheep siphon off of the democrat side.

---