NY versus Illinois
I was looking over the exit polls for Illinois and New York and there's an interesting pattern to the data. In her home state, Hillary Clinton did better among pretty much all groups than she does nationwide. Still, Obama won his core constituencies -- young people and African-Americans. In Illinois, by contrast, Obama pretty much ran the table, eking out narrow wins even in bad demographic groups like old people and Hispanics. He even won women 64-35.
Now maybe this just reflects that fact that New York was more seriously contested than Illinois. Obama didn't put resources into trying to win the state per se, but he was playing for New Jersey and Connecticut in the same media market and did some fundraisers and rallies over the months. But on the other hand, it does fit a broader pattern, namely that the better people keep to know Obama, the more they seem to like him. Every state he campaigns in shows a strong upward trajectory, and in the state where he's best-known, even the most skeptical demographic groups come around to him. Hillary Clinton, by contrast, has her base and it's a big base, but the tendency is to only drop down from that level.