Findings:
For some very strange reason, the exit polls show that in Mississippi, young voters became more Republican. This doesn't make sense since Obama was able to still win young voters, but Kerry, the northeastern "elitist liberal", actually won 63% of these voters. I had asked a young, black college professor from MS about that and she said the 63% could be because of a number of reasons: (1) young voters in Mississippi opposed the Iraq War on religious grounds, (2) young voters in Mississippi are much more mixed racially than the older generation which is whiter, (3) even in Mississippi, young voters are more progressive.
re: Mississippi
It could be that
(1) Obama is black, and white Mississippians are not accustomed to voting for blacks for any office. Mississippi politics are really scummy irrespective of ethnicity, and Obama looks like the sort of leader that white Mississippians associates with black-majority places in Mississippi in which white politicians have no chance to win. Machine politics are the norm in Mississippi, even in rural counties. (White machine politicians are no better). Kerry is white.
As far as Mississippi and the differences between 04 and 08 go. Keep in mind that not all polls are perfect. You will generally have 1 poll out of 20 which is outside the MOE. So when you have a set of 50 exit polls, you will likely have 2 or 3 polls which are off by a bit. This appears to be the case in Mississippi in 04, and Maine as well
Smash's post is more likely accurate. Even if 45% of younger Mississippians (in the electorate) are black and all young black Mississippians voted for Kerry, that would translate into 33% of young white Mississippians voting Kerry, which compared to 14% of all white Mississippians, is highly unlikely.
True though Louisiana whites had a strong GOP swing, though it's possible people blamed the Dem Blanco moreso than Bush.
Up until this election, the Atlanta suburbs were very Republican. A lot of the suburban counties had strong Obama swings--though I'm not sure if this is juist from blacks moving to the suburbs or if there's been an anti-GOP trend among suburban Atlanta whites.