DES MOINES -- Oprah's celebrity is HUGE in South Carolina and pretty big in New Hampshire, but the enthusiasm is simmered down in Iowa.

Where Barack Obama's campaign had to change venues in South Carolina to accommodate the interest and where they rented the largest stadium in New Hampshire for the joint campaign stop there, the two events scheduled for Iowa tomorrow afternoon haven't sold out.

That's not to say that Oprah doesn't command large audiences in Iowa -- she does.

Maybe it's the winter. Maybe it's the 10,000+ seats the campaign has to fill at each venue.

Or maybe it's the skepticism that Iowa Democrats have for celebrity endorsers.