From PPP:

One of the most amazing things in our polling over the last month has been how dreadfully bad Barack Obama’s approval numbers are with likely voters in a lot of states that he won by large margins in 2008. We’ve polled 12 states since the beginning of September that Obama won by at least 9 points and in all but 3 of those states- Hawaii, California, and New York- his numbers are under water.
The states where we do now find Obama with negative numbers that he won easily in 2008- Michigan, Wisconsin, New Mexico, New Hampshire, Delaware, Maine, Connecticut, Colorado, and Illinois.

More here.