The vice president will finally be introduced in Thursday's episode of Scandal - and she's the polar opposite of President Fitz (Tony Goldwyn).

"She's kind of like a combo physically between Dianne Feinstein and Nancy Pelosi, but when she opens her mouth she's pure Michele Bachmann," says Kate Burton, who plays Sally Langston, the Tea Party conservative who was once Fitz's enemy. (She sounds peachy!) Burton is all too familiar with playing a strong female matriarch, having portrayed Ellis Grey on Grey's Anatomy, a role that surely came in handy when taking on the VP of the United States.

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But who is Sally really? And could she be behind the mysterious blackmailer who's giving the President so much trouble? TVGuide.com caught up with Burton to get the scoop on that and her reunion with her Grey's Anatomy ex-husband:

What kind of person is the vice president? Kate Burton: She's an absolutely strict, conservative Southern republican. It's just really fascinating to play her because things came out of my mouth that would actually never come out of my real mouth. She is so arch-conservative and the president is so moderate. I wanted to play her and obviously not make her any kind of cartoon liberal or conservative. I wanted to make her a real person. We know what a real person she is because there are things that get to her more than anything: anything to do with her daughter. She is a mom who became a politician and she's ruthless, but she's also got a heart.

Fitz and Sally were actually running against each other in the presidential campaign. What can you tell us about their road to the White House? Burton: The reality is, when we do the flashback [in next week's episode], we discover that she was actually in the lead. She was doing really, really well. As things happen in politics, something turned everything around and then suddenly he starts becoming much more appealing. Their competition was very real. It was a real clear choice between the two of them, and she was gaining. It was a juggernaut and they didn't quite know how to stop her.

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Is Sally still angry that Fitz beat her to the presidency? Burton: If you read about anything where there is a very powerful contest between two very different people, like Lyndon Johnson and John Kennedy, suddenly Kennedy ascends and he asks Johnson to be his vice president. It's not easy because Johnson's used to being in a very powerful position. I'm also on Veep on HBO and that's our running gag: When you become vice president, you lose your power. It is hard for Sally, but she's a politician. She is very, very deeply religious, by the way. I can't believe I haven't mentioned that until now! She's a woman of the founding faith. So she uses her faith to help her with how disappointed she is with not being able to win the presidency, or the nomination.

Would she do anything to get into the Oval Office? Could she be behind the blackmailing? Burton: I think she's pretty determined. She's pretty ruthless. It's going to be a very uneasy partnership between she and Fitz. And of course when she discovers what is happening with Amanda Tanner (Liza Weil), she operates on a fairly moral high ground. What I love about Tony is that you don't know whether to like him or dislike him a lot of the time, and I think the same with me. You probably will not know whether I was the good guy or the bad guy. I think I'm both, and I think he is too. Both of them have these very manipulative chiefs, Billy Chambers (Matt Letscher) and Cyrus Beene (Jeff Perry), and those Chiefs of Staff will stop at nothing.

Billy is Sally's trusted right-hand man, but can he really be trusted? Burton: I think she thinks so. I think that she completely trusts him. He's such a clean-cut, All-American-looking guy that you think, "Oh yeah he's absolutely trustworthy." He gets overcome with wanting her to succeed to where he loses his grasp of reality. It's very fun because I think it's very surprising what happens as the story winds on.

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Scandal: Grey's Anatomy's Kate Burton Makes Her Debut as the VP