Delaware Senate GOP candidate Christine O'Donnell said in 2008 that then-Sen. Barack Obama was "anti-American."

O'Donnell suggested during an interview on Fox News that then-presidential candidate Obama was "anti-American," and attempted to explain why.

"I would prefer Barack Obama because he is so liberal, that — he's anti-American," O'Donnell said when asked if Republicans would prefer to face Obama or his then-primary opponent, Hillary Clinton.

"Let me explain why. He's beating the change drum, but let's look at the change. He did not vote for English as the official language. What does that say?" O'Donnell added. 

The comments were first flagged by Political Correction, a project of the liberal Media Matters Action Network.

GOP leaders have slowly sought to cast O'Donnell, who upset Rep. Mike Castle on Tuesday night in a Republican Senate primary, as not too far out-of-step from the rest of the party. House GOP Conference Chairman Mike Pence (Ind.) said O'Donnell's views on repealing healthcare reform were within the Republican "mainstream," and Senate Minority Leader Mitch McConnell (R-Ky.) suggested Tuesday that he'd back her if she won the primary.

But O'Donnell's history has also come under scrutiny, fueled by Democrats who look to cast her as extremist. Opponents of O'Donnell have circulated video of her on an MTV special in the 1990s in which she opposes masturbation for religious reasons.

Questions have lingered, too, over O'Donnell's college record and whether or not she'd faced a lax lien over outstanding student loans.

O'Donnell called those claims "unfactual" during an appearance on ABC's "Good Morning America" on Wednesday.

"I'm not a trust fund baby; most Delawareans can relate to having to work hard to pay for their own college education," she said. "I was never dishonest about that."

O'Donnell wouldn't be the first polarizing Republican figure to suggest such a thing about Obama. Rep. Michele Bachmann (R-Minn.) in 2008 accused Obama of holding "anti-American views," spurring a last minute Democratic onslaught that almost cost Bachmann her seat.