I wrote this at Bleeding Heartland yesterday:
http://www.bleedingheartland.com/2016/02/29/is-the-gop-headed-for-a-brokered-convention/
Most people really haven’t looked at the delegate math. It is unlikely that Trump will have get more than half the delegates tonight. A shift of 2 points in either direction though could have enormous implications: many states have 20% thresholds, and both Cruz and Rubio are close to them.
I still do not believe Trump will get the nomination.
On the Dem side a 6-5 split for Bernie would be a miracle, and would keep this race very much alive (the idiotic musings of those who never supported Bernie and now pretend that Bernie supporters have any reason to listen to them notwithstanding).
A 7-4 split would be ok. In either event he has to win Michigan to have a real shot. He is behind there, and the numbers don’t look good in general.
But then, as I wrote years ago, there are plenty of instances where primaries turned on a single primary.
http://www.dailykos.com/story/2004/01/31/13451/-A-remembrance-of-primaries-past-why-this-race-is-not
-over