Interesting numbers break-down from Sean Trende. State-by-state delegate analysis always pleases the geek in me.
"This could prove critical in a drawn-out race. The reason is simple, and yet not well-known. The RNC has provided that states holding primaries before April 1 must allocate delegates proportionately. But after that date, states may opt for winner-take-all primaries, and many of these states have done so. In other words, we could have a situation where a conservative candidate (or a pair of conservative candidates) does well in the first three months, but has to give some delegates to the more moderate candidate. This is similar to what happened to Clinton, who won crucial primary battles late in the game, but couldn’t make much headway in the delegate count because of how these delegates were allocated. So despite winning the majority of primaries, the conservative candidate could end up with only a small lead in delegates over the more moderate candidate. If the moderate candidate then performs well in April or afterward, he could quickly rack up enough delegates to break away and claim the nomination."