There's no need to "change the delegates' minds", since all of the delegates are already Ron Paul supporters. The rubes who are voting in these primaries/caucuses, vote and go home, thinking they've "done their part". RP has told his supporters to stick around and actually volunteer to be delegates. It's a job that not many want to do. RP is setting up a brokered convention (why else would we see first one candidate, then another, rise to the top?), so that during the first round of voting in Tampa, no one gets the majority of votes, and the delegates are then free to vote for whomever they want. The second round of voting will see RP win a supermajority of votes.
It is necessary to do it this way, since the GOP party establishment is doing everything it can to cook the numbers.