Trump got 4 of the 5 states yesterday and the Nothern Mariana Islands. Great day for him.
In a field starting at 6 he has received close to 47% of the delegates. He needs 59% going forward starting in a field of 3.
Despite the media narrative, Trump has an excellent shot meeting the delegate total of being the nominee.
As for the brokered convention, as of today, Trump is the only candidate that could be nominated under their current rules as he is the only one that has won the majority in at least 8 states. Ted Cruz currently has 4. It is possible he won't meet that requirement.
Now if they change the rules to undermine Trump it would be like the soviet union and fly in the face of democracy. The GOP establishment would be exposed as total frauds.
IMO the establishment is just posturing, they will eventually back him.
As for Kasich it is impossible for him to be the nominee in any scenario.