PPP: Santorum leads Romney by 15-points in Michigan (one of Mitten's home states)

[Sheepshank]

18. I don't think so...otherwise why have delegates and why not just use the voters results?

It would appear, the delegates just take cues from the votes

These delegates are supposed to take their cue from the voters who cast ballots during their states' primaries and caucuses, though each party's rules make it possible for multiple rounds of balloting and horse trading if no candidate is able to gain a majority on the first ballot. But since 1976, no major party convention has opened with the identity of the nominee in question.
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During the primary process, "the party is choosing their candidates, which is very different from the public choosing a candidate," says Norman Ornstein, an expert on U.S. politics at the American Enterprise Institute think tank. The goal is to "narrow it down to the candidates who most represent the party, and who have the greatest chance of winning," says Ornstein. At least, he says, "That's the theory. It doesn't always work that way."

Each state make various decisions as to how they hold or re-vote in primaries. There is wiggle room for sure.