Every author knows that a recommendation from Oprah's Book Club can catapult you up the best-seller lists. But what is an Oprah endorsement worth for a possible presidential candidate?

Well, we're about to find out. According to the Hotline, Oprah will tonight tell those pining for a Winfrey presidential bid to get behind Barack Obama instead. To add yet more fuel to the Obama fire, there's also a laudatory profile of him in New York magazine that describes covering him as "like going to view the Mona Lisa at the Louvre. All you see are the backs of people's heads." All this on a day when a poll shows that Hillary Clinton would lose the swing state of Iowa to every Republican candidate she was polled against.