Not much suspense about the outcome, but there is plenty to watch for in South Carolina

No one really doubts that Obama will win South Carolina on Saturday, though Clinton could still benefit from a surge in the share of white vote and in the proportion of whites she gets. Like most victories that are expected, the margin will determine the coverage Obama gets on Saturday: (1) Will he beat Clinton decisively? And (1) will he cut his losses among whites?

If both conditions are fulfilled, Obama could certainly get a significant bounce heading into February 5th. Otherwise, his win will be covered but remain unlikely to change the dynamics of Super Tuesday. And Clinton knows that she needs to minimize her involvement in the Palmetto State to make a defeat seem unimportant (though she was ahead here for much of the fall). She has barely campaigned in the state, and she was in... New Jersey last night, one of the states she must win come February 5th.

And with that we got two new polls today showing Obama leading -- albeit his movement goes in opposite directions:

• In the ARG survey, Obama increases his lead a bit and is now up 45% to 36%, with Edwards far behind at 12%. Clinton's lead among white voters is particularly higher than usual (52% to 24% for Obama, with Edwards at only 16%), while Obama crushes her 71% to 17% among blacks. ARG also has whites making up 55% of the electorate, which is a higher proportion than usual.
• The Zogby poll, meanwhile, finds that Obama has slipped from 43% to 39% in a day, with Clinton at 24%. Edwards has risen to 19% -- threatening Clinton's second place. More surprisingly, Obama is going down among black voters (down to 56%) and Edwards pulled in 27% for Wednesday alone, increasing every day -- and passing Clinton.

There is no question that a third-place Clinton showing is not expected and would generate a lot of bad press for the New York Senator -- perhaps even similar to that she got after Iowa. With all her attempts to distance herself from the state and seem unconcerned, Clinton should be very careful here. At the same time, Edwards could only take second with a sizable lead among whites. After all, he is nowhere among black voters and that is a significant disadvantage he has to make up.

The problem for Edwards at this point might be financial. His campaign just e-mailed out a plea to its supporters to donate money so this new ad can air: "I'm contacting you with an urgent request. If we can raise $65,000 today, we can get a great campaign spot featuring John on the air in South Carolina for the last 24 hours before the primary this Saturday." Of course, this is also probably an exaggeration of the campaign's financial trouble, but candidates rarely make so direct appeals unless they really can't air an ad (remember Thompson going off the air for 24 hours in Iowa in the week leading up to the caucuses).

One more consideration related to Edwards is what effect keeping him in the race longer could have on Super Tuesday. Both candidates were expecting Edwards to get a second whooping in South Carolina after Nevada's 4% and have nowhere to go but fade, opening up a huge number of votes on February 5th. If Edwards gets second or a strong third (which is definitely possible), don't expect him to go anywhere or surrender his 15% to his rivals. Edwards is still in a position to get many delegates on Super Tuesday and possibly play king-maker if it all goes to a convention. And that prospect must be terrifying to both the Obama and Clinton campaigns, who would much rather have things under their direct control.

Update: More confirmation of an Edwards rise in South Carolina comes from SUSA's latest poll from the state. It shows Obama at 45%, with Clinton at 29% and Edwards at 22%. A week ago, it was Clinton at 36% and Edwards at 15% -- a clear trendline. Clinton gets 37% of the white vote to Edwards's 33%, while Obama crushes Clinton among the black vote 73% to 18%. To overtake Clinton, Edwards will probably have to win the white vote by at least double-digits, so he is not quite there yet.