Pop quiz, hotshot: With two days left before what could be the most important single day in the race for the Democratic presidential nomination, to whom do you turn for that all-important last push, especially in a key state?

Well, if you're the campaign of Sen. Barack Obama, you might think about putting the candidate himself out there. Then again, you might want to turn to seemingly the only person in the U.S. who can attract a more worshipful audience these days: Oprah Winfrey. And that's what the Obama campaign has done; it has just announced that Winfrey, who campaigned for Obama in December as well, will appear in Los Angeles with Michelle Obama and Caroline Kennedy on Sunday. They're not offering any more detail than that yet, though.

Elsewhere, some prominent Democrats seem ready to sit out Super Tuesday, especially those who themselves were running for president this cycle. Former North Carolina Sen. John Edwards held off from endorsing anyone when he dropped out of the race earlier this week. New Mexico Gov. Bill Richardson will reportedly wait until after Super Tuesday; Connecticut Sen. Chris Dodd announced a press conference for Friday for the sole purpose, reportedly, of announcing that he wouldn't endorse. (The press conference was canceled as a result of travel delays.) And despite some last-minute speculation, it appears that former Vice President Al Gore won't be announcing his pick either.