Missouri Senate candidate Todd Akin is pushing back against a 5 p.m. deadline Tuesday to remove himself from the race, as GOP leaders hope to redeem their party and take back power in the upper house.

The Washington Post reported Akin released a new ad called "Forgiveness," in which the candidate says "Rape is an evil act… The mistake I made was in the words I said, not in the heart I hold."

Watch the 30-second spot below.

But his mea culpa may not be enough to save the campaign. CBS News' Chief White House correspondent Norah O'Donnel said on "CBS This Morning" that the remark cost him around $10 million.

"Top republicans have called him and said you're done. We're not going to give you $5 million from the Senate committee. Crossroads, an independent super PAC, has said that they are not going to give him $5 million. This has already cost him $10 million. I have heard republican say he does not have enough money in his account o win. That's why he put out that fundraising appeal.

"As far as the Democrats, you heard the president come before the press corps after avoiding the press corps for eight weeks, to slam the statement and also to try and tie the comments to the Republican Party platform and to a bill Akin has co-sponsored with [vice presidential candidate] Paul Ryan to try and make this larger point about the Republican Party and women's rights. So, you see the Democrats saying at this point, he, we hope Akin stays in because Claire McCaskill was the most endangered democrat in the United States Senate now has a hope of victory."

If Akin fails to withdraw before 5 p.m. today, he'll have to obtain a court order to do so, and will have until Sept. 25 to petition a court to be removed from the ballot. 

And in one more twist for the GOP, New York Daily News reported the doctor linked to Akin's questionable medical claims about "forcible rape" endorsed the now presumptive Republican presidential candidate Mitt Romney in 2007.

Dr. John C. Willke published a 1999 article explaining his theory that women are unlikely to become pregnant in the event of "forcible rape."

And he stands by his theory 13 years later, saying Monday in an interview with The New York Times: 

“This is a traumatic thing — she’s, shall we say, she’s uptight,” Dr. Willke said of a woman being raped, adding, “She is frightened, tight, and so on. And sperm, if deposited in her vagina, are less likely to be able to fertilize. The tubes are spastic.”

Other medical experts have dismissed the theory, calling it "just nuts."

And Romney has taken significant measures in the past few days to distance himself from Akin's comments. But he sang a different tune in 2007 with the announcement of Willke's endorsement.

From the Daily News:

In 2007, however, Romney’s campaign had embraced Willke – who served as president of the National Right to Life Committee for a decade. In a statement announcing Willke’s endorsement, his campaign said the doctor would be “an important surrogate for Governor Romney's pro-life and pro-family agenda.”

"I am proud to have the support of a man who has meant so much to the pro-life movement in our country,” Romney said in a statement. “He knows how important it is to have someone in Washington who will actively promote pro-life policies."

Willke also touted Romney’s commitment to anti-abortion issues.

"Unlike other candidates who only speak to the importance of confronting the major social issues of the day, Governor Romney has a record of action in defending life,” Willke said at the time.

Romney's campaign has not responded to recent questions about Willke's endorsement.

For more on Akin, check out Neon Tommy's coverage here.

Reach Executive Producer Catherine Green here; follow her here.