From the recent Rasmussen Reports primary poll in Mississippi:
One measure of a deepening divide in the party is that just 56% of Obama voters have a favorable opinion of Clinton. Just 34% of Clinton voters have a favorable opinion of Obama.So among Clinton supporters in Mississippi, only about half are "even somewhat likely" to vote for Obama in November.
If Obama is nominated, just 47% of Clinton voters say they are even somewhat likely to vote for Obama in the general election against John McCain.
If Clinton is nominated, 65% of Obama voters say they are at least somewhat likely to vote for her against McCain.
Sure, the Democratic primary has been acrimonious of late. But there's something more going on here. Who are these folks that would vote for Clinton in the primary -- but McCain in the general election? They are likely white Southern Baptists (and probably leftover Solid South Democrats), a group which, as I've been emphasizing all year, is not kindly disposed toward Barack Obama. I suspect the reason ultimately might have to do with Obama's race, but that's a subject for another day.
Now, how much of a problem is this for Obama? Probably not all that much. If we look at this subgroup in Mississippi, for instance, we're talking about half of the 40% of Clinton supporters in a state in which Democrats won about 40% of the vote in 2004. So 50% x 40% x 40% = about 8% of the voting pool.
But these voters are concentrated in states where Obama is not likely to be competitive anyway -- the states that we're referring to as the Deep South. In states that are even moderately more liberal -- states like North Carolina and Virginia in the South Coast region -- Obama's advantages with black voters and independents are enough for him to run at least evenly with Clinton. But in places like Mississippi, Tennessee, and Oklahoma, Obama has very little chance.