John Edwards needs a win — badly — to keep his presidential hopes alive.

But that elusive win may not be coming soon. Polls show him trailing Barack Obama and Hillary Rodham Clinton in Saturday’s important South Carolina primary.

It’s starting to look more and more like a two-person race for the Democratic nomination.

But my guess is that Edwards will hang on, at least until the Feb. 5 so-called “Super Tuesday’’ or “Super-Duper Tuesday,’’ or “Tsunami Tuesday,’’ or whatever other hyperbole is being used for the day when 22 states will hold primaries or caucuses.

If Edwards bows out, it will be interesting to see whether he throws his support to Obama or Clinton. But don’t look for him to be chosen as the vice presidential nominee.

That’s hard to imagine after he tried that four years ago as John Kerry’s running mate.

A ticket of Obama-Clinton or Clinton-Obama would certainly energize Democrats for the fall campaign. That may not be possible, especially if the two continue to criticize each other during the campaign.

But the possibility is interesting. What do you think?

— John Guerriero