Did we mention that in some states Republican delegates are under no obligation to vote in agreement with the people who sent them to the convention?
They are known as unpledged, or unbound, delegates. It’s unlikely they would vote for a different candidate at the party convention, but it is possible. And their numbers are not small: In fact, about 20 percent of the allotted delegates of both parties are of the unpledged variety. They won’t officially register their preferences until the party conventions this summer.
One effect of this system, particularly on the Democratic side, is that party leaders retain critical influence in the process.”