Here’s Rick Santorum discussing both of these issues on Fox News earlier:

I think Oprah attracts more women than Bill Clinton, no question there. For one, Oprah’s never been accused of rape.

Bill Clinton appeals to the 90s Democrats who have it in their mind that America was a great and shining country under Bill Clinton’s administration. Therefore, that reflects on Hillary for those people.

Bill Clinton is old news compared to Oprah actually endorsing a candidate for president.

Update

Here’s the video of Oprah’s entire speech for Obama from Iowa:

Video: Oprah’s Entire Speech for Obama from Iowa