The controversial comments led Republican vice presidential hopeful Paul Ryan, a Wisconsin congressman, to withdraw his endorsement of Roger Rivard just hours before Ryan was set to debate Vice President Joe Biden.

It was the second time Ryan has withdrawn an endorsement from a fellow Republican due to offensive rape comments.

Missouri congressman Todd Akin drew widespread condemnation for declaring in August that a woman's body can prevent conception in cases of "legitimate rape" as he tried to explain his opposition to abortion even in cases of rape.

Ryan, who also opposes abortion in cases of rape, is expected to be pressed on his pro-life views during the debate.

Rivard, a 60-year-old state representative, first made the statement when discussing the case of a local high school student who had been charged with sexual assault for having sex with an underage girl in the school's band room.

The Chetek Alert paper quoted him in December as saying that his father had warned him "some girls rape easy" -- meaning that some girls could decide later that sex wasn't consensual.

He doubled down on the comments in an interview with the Milwaukee Journal Sentinel Wednesday, saying that he took his father's warnings about the dangers of premarital sex seriously.

"He also told me one thing, 'If you do (have premarital sex), just remember, consensual sex can turn into rape in an awful hurry,'" Rivard told the paper.

"Because all of a sudden a young lady gets pregnant and the parents are madder than a wet hen and she's not going to say, 'Oh, yeah, I was part of the program.' All that she has to say or the parents have to say is it was rape because she's underage. And (my father) just said, 'Remember, Roger, if you go down that road, some girls,' he said, 'they rape so easy.'"

Rivard went on to say: "What the whole genesis of it was, it was advice to me, telling me, 'If you're going to go down that road, you may have consensual sex that night and then the next morning it may be rape.' So the way he said it was, 'Just remember, Roger, some girls, they rape so easy. It may be rape the next morning.'"

About three hours after speaking to the paper, Rivard -- who is engaged in a tight re-election race -- sent a statement to the Sentinel in which he acknowledged that "rape is a horrible act of violence."

"Sexual assault is a crime that unfortunately is misunderstood and my comments have the potential to be misunderstood as well," his statement said.

"I have four daughters and three granddaughters and I understand the importance of making sure that awareness of this crime is taken very seriously."

But activists said his initial statement belies his inability to comprehend the realities of sexual assault and are part of a broader problem of blaming victims.

"Unfortunately, comments like these are all too common, and an indication of ways in which the culture is generally undereducated about what sexual assault is," Pennie Meyers of the Wisconsin Coalition Against Sexual Assault said in a statement. "Sexual assault remains an underreported and underprosecuted crime."

Rivard, who is married with six children and ten grandchildren, said in his campaign biography that he learned the "value of a hard day's work at a young age" while working at his parent's restaurant in Rice Lake, Wisconsin.