This, to me, is an interesting empirical question, and could make a huge difference in the election, particularly in close states, but also in the popular vote margins.
Are people who are less enthusiastic about their candidate more likely to leave the polling station when the line is long?
As we know, one of the big differences in polling between Obama and McCain supporters, which does not show up in the top line numbers is enthusiasm. Obama has a huge advantage over McCain, both in terms of poll results, and when you compare Obama's huge crowds with McCain's sparse ones.
So, the question is, does a moderately enthusiastic voter ditch the long line earlier than the enthusiastic one, and if so, by how much? Of added interest, how much does the GOTV effort factor into this number? Are people well prepared to wait, in terms of expecting it, in terms of having food and water, etc., in terms of being reminded of the importance of STFIL?