1. In one precinct, the Edwards camp has set up next to Joe Biden's supporters. The Edwards people are counting on Biden not reaching the 15% threshold, which would mean his supporters would need to re-vote. Hillary Clinton and Barack Obama's people are on the other side of the room, which is a long walk through the Edwards supporters, who will undoubtedly be trying to swing them their way. If for no other reason than Biden's people get fed up with the walk, and thus stay close and caucus with Edwards, then Edwards benefits. It seems so basic and, to a point, primitive, but a candidate can use all the help he can get, no matter how he gets it.
2. Some precinct captains for the second-tier candidates who receive 10-15% of the vote are urging the captains of the winners of the first vote of their precinct to send them voters to reach the 15% benchmark. The front runner would still win the precinct, but the second-tier candidate would be able to have their votes counted. If the winner of the precinct does not give them their extra people, then the second-tier candidate's captain will send his people to another front runner, which would almost ensure that the winner of the first vote would lose on the re-vote.