When voting in Approval, remember that:
1. There is no reason to not give max points (an approval) to your genuine favorite(s)
2. There is no reason to give more than min points (no approval) to someone who isn't quite as good as your favorite(s), unless, otherwise, someone worse might win.
The results of the 2008 poll, and the results-so-far in this poll, give you an idea of what is likely. For instance, in 2008, and in this poll so far, the Republican candidates get very few points, and aren't even close to winning.