Pollster.com has a very interesting look at the last night's numbers. Essentially, Scott Brown managed to get every single McCain supporter to show up and vote last night, while Coakley underperformed Obama by greater than 20%. Hard to conclude anything other than "motivating the base" made the difference here. What you cannot tell from these numbers is whether Brown managed to get a significant number of Obama voters to switch to him, or simply if many who voted for Obama in '08 just stayed home rather than vote for Coakley. My guess would be the latter, but what do I know.