14% isn’t a bad number for Palin, taking into account she’s not even in the race. If she actually gets in she could probably pull a point or two more from each of the candidates currently in. Knocking Romney into 3rd wouldn’t bother me one bit.
I keep seeing Palin supporters making this feeble claim. The reason most candidates get a bump when they enter the race is because they are not well-known, so they pick up a lot of people who are taking a look at them for the first time. Palin has almost 100% name recognition, and she has been campaigning almost non-stop for three years, if you include her TV shows, Tea Party events, bus tours, Fox News gig, etc. Almost everyone knows her and almost everyone has an opinion - for almost 2/3 of them, that opinion is negative. So she is not going to suddenly get a bump in the polls because she jumps in. To do that, she is going to have to start changing people's minds about her.