This has been changing, but some conservatives haven't gotten the memo.
Last year, Roger Ailes quoted Phyllis Schlafly that a husband forcing his wife to have sex with him should be treated like a woman being raped by a stranger:
A man’s life has been sacrificed, and three children have been denied their father by malicious feminists who have lobbied for laws that punish spousal rape just like stranger rape and deny a man the right to cross-examine his accuser. They have created a judicial system where the woman must always be believed even though she has no evidence, one in which the man is always guilty. [emphasis Ailes’]
It’s nice that Schlafly acknowledged, at least implicitly, that it is possible for a man to rape his wife — but at the same time, she is quite explicit that raping one’s wife shouldn’t be punished like raping a stranger (or, presumably, someone you know but aren’t married to). Why is this? Do wives deserve less legal protection? Does Schlafly simply believe that marriage continues to qualify as consent to sex at any time and, therefore, that husbands who force their wives to provide sex shouldn’t be treated like “real” rapists?
Recently, Washington University decided to reward Phyllis Schlafly for her work on behalf of ideas like women can't really be raped by their husbands and she gave an interview to the student newspaper where she reiterated that she does indeed believe this:
Could you clarify some of the statements that you made in Maine last year about martial rape?
I think that when you get married you have consented to sex. That's what marriage is all about, I don't know if maybe these girls missed sex ed. That doesn't mean the husband can beat you up, we have plenty of laws against assault and battery. If there is any violence or mistreatment that can be dealt with by criminal prosecution, by divorce or in various ways. When it gets down to calling it rape though, it isn't rape, it's a he said-she said where it's just too easy to lie about it.
Was the way in which your statement was portrayed correct?
Yes. Feminists, if they get tired of a husband or if they want to fight over child custody, they can make an accusation of marital rape and they want that to be there, available to them.
So you see this as more of a tool used by people to get out of marriages than as legitimate-
Yes, I certainly do.
Source: Student Life (via Feministing, emphasis mine)
There are several key elements in the above which must be kept firmly in mind. First, according to this defender of "traditional marriage" and traditional social roles for women, marriage (at least from the women's perspective) is "all about" consenting to sex. It's not about love, companionship, money, procreation, or anything like that. It's all and only about making yourself sexually available to a man anytime he wants it. Women who marry pre-consent to sex whenever and however their husbands demand it. Because they pre-consent to sex, it's not possible for any forced sex to really be rape.
Second, forced sex isn't violence. Phyllis Schlafly does object to "violence or mistreatment" of a woman by her husband, but since she doesn't object to a woman being forced to participate in sexual activity with her husband, then the conclusion is that forced sexual activity doesn't qualify as "violence or mistreatment." I wonder if a man forcing another man to engage in sexual activity would qualify as "violence or mistreatment"? Probably, since they can't have a "real" marriage.
You’d think that a “real” conservative would support principles like equal protection of the laws and enforcing laws against actions which harm others. If this is so, then the question becomes: is Phyllis Schlafly a “real” conservative, or has conservatism in American degenerated so far that it is no longer recognizable? I can't claim to know for sure, but either way I don't think that anyone who does care about equality and who does care about women should have anything whatsoever to do with it.