One tactic is to come up with a reason to demand that the polls stay open later ("irregularities," large, late crowds, etc). Then, based on internal polls, they determine how many "new" voters and "dead" voters they will need to ship in or make up.
The little nuts and their ilk wait until the polls are about to close. They then move in and cast the votes for the people who did not show up.
PS to freespirited: I live in Jersey and I have never, ever heard anyone say New Joisy, unless they are from lawnguyland.
BUMP
They only come out after the polls close and the numbers to fabricate are known.