Daily Beast:

Donald Trump introduced his presidential campaign to the world with a slur against Mexican immigrants, accusing them of being “rapists” and bringing crime into the country. “I mean somebody’s doing it!… Who’s doing the raping?” Donald Trump said, when asked to defend his characterization. It was an unfortunate turn of phrase for Trump—in more ways than one. Not only does the current frontrunner for the Republican presidential nomination have a history of controversial remarks about sexual assault, but as it turns out, his ex-wife Ivana Trump once used “rape” to describe an incident between them in 1989. She later said she felt “violated” by the experience.

Michael Cohen, special counsel at The Trump Organization, defended his boss, saying, “You’re talking about the frontrunner for the GOP, presidential candidate, as well as a private individual who never raped anybody. And, of course, understand that by the very definition, you can’t rape your spouse.

“It is true,” Cohen added. “You cannot rape your spouse. And there’s very clear case law.”

Actually... that's not true. You can rape your spouse.

A man still needs to obtain his wife's consent before he fucks her. And a woman needs to obtain her husband's consent before she fucks him. (Same goes for men and women in same-sex marriages.) But almost as shocking as Trump's lousy lawyer's misinformed, rapey comments? Being reminded of how recently marital rape wasn't a crime. It didn't become a crime for a man to rape his wife in New York State until 1984. In that year, the New York State Supreme Court overturned a state law barring prosecutions in cases of marital rape. (Judicial tyranny! Unelected judges!) This court's decision helped to further undermine the traditional definition of marriage.

Traditionally the wife was the property of her husband. She was an extension of her husband—they were one flesh—so a man could no more rape his wife than he could sexually assault his own right hand. From a 1984 report in the NYT on the New York State Supreme Court's decision:

The legal foundation for excluding husbands from prosecution for rape dates to the 17th century, when Sir Matthew Hale, a Chief Justice of England, wrote: ''The husband cannot be guilty of a rape committed by himself upon his lawful wife. For by their mutual consent and contract, the wife hath given up herself in this kind.'' U.S. Case That Changed Law. That sentiment was echoed by John Rideout, of Salem, Ore., who went on trial in 1978 on charges of raping his wife, Greta, while they were living together.''You're my wife, you do what I want,'' Mr. Rideout said. He was acquitted. Several states changed their rape laws after his trial.

Some Christian conservatives still make this argument:

Biblically, we do not believe marital rape is possible. Scripture clearly teaches in 1 Corinthians 7 that a wife’s body is her husbands and a husband’s body is his wife’s. We believe consent is given at marriage. We believe the teaching on marital rape is a poison in the well of women’s hearts and minds towards their husbands and marriage & does much damage.

States didn't start banning marital rape—they didn't start treating marital rape as a crime—until the late 1970s. Marital rape didn't become a crime in all 50 states until 1993. (Some states, most notoriously South Carolina, still treat marital rape cases differently—it's punished less severely, and "the law requires a higher level of violence to be used.") And banning marital rape—deciding that wives were not the property of their husbands, that wives could say no to their husbands, that a woman had not "given up herself" to violence, abuse, and rape when she married—is one of the many, many ways that straight people redefined the institution of marriage during the 20th century.

The cumulative effect of all those changes? Once the gender roles and expectations were stripped out of the legal definition of marriage—once opposite-sex marriage was no longer a property exchange between two men (the husband-to-be and the father)—no logical case could be made for excluding same-sex couples from the institution of marriage as straight people (re)defined and practiced it.

Still... you gotta wonder why defenders of traditional/biblical/retrograde marriage are so quiet this morning. Why hasn't NOM come to the defense of Donald Trump's awful lawyer?

UPDATE: Note from a reader...

I applaud your pointing out that it has not always been illegal to rape one's spouse, and the history you presented was all 100% accurate (I wrote my doctoral dissertation on this subject). But, as a feminist—hell, as a human being—I take issue with the use of the phrase "marital rape." This linguistic construction discursively separates the crime of raping one's spouse from "regular" rape, which is typically imagined as violent assault by a stranger. I think it would go a long way toward accepting the rape of one's spouse as a crime if we just call it "rape." Sex without consent is always rape, and no qualification is necessary. Modifying the word rape with the adjective "marital" implies that this crime is somehow lesser because the perpetrator in question was the husband or wife. But studies have demonstrated that the violation felt by the victim/survivor of rape by one's spouse is often equal to the sense of violation felt by victims/survivors of stranger rape.