Believe I told Al a few days ago that I wouldn't be surprised in the LibDems underperformed a bit (because of movement back to Tories and Labour). We'll see whether the exit polls are right or not on this one.
This would be more than "a bit" of underperforming, this would be essentially treading water with their 2005 result.
What it would say is that there was a lot of flirting that went on, and then things went back where they should be. The numbers really aren't important here, just understanding that this movement was likely.
