I would not want to give away the whole movie, but Michael is triumphant over a government attempt orchestrated by his rival Hyman Roth to take Michael down. He uses his resources, his powers and his intelligence to figure out how to psychologically get to the government's star witness. His ploy is amazing in how cold Michael was to his brother in getting information out of him, as well as the ingenuity that Michael used. A guido mobster would not think like Michael, which is why he rules the Mafia kingdom. I have never understood why NBA players and rappers idolize Scarface when Michael Corleone is the real kingpin. Michael is packing to go home with Kay and the kids, and Kay comes in to tell him she is not going back to Tahoe. What ensues is a screaming match between the two.
Here is how Wikipedia describes it.
Afterwards, Michael violently prevents Kay from leaving with their children; she retaliates with the revelation that her miscarriage was actually an abortion.
What really happens is that Michael tries to calm Kay down, and tells her she is just upset over the miscarriage that she had of their third child. As the head of an empire under intense stress, Michael tries to talk Kay into staying with him, blaming the demands of work. Here is the additional frustration of this blatant Wikibias. Wikipedia's quotation page directly refutes the progressive line above. Let's go to the script (my notes are in bold).
Michael: What do you want from me? Do you expect me to let you go? Do you expect me to let you take my children from me? Don't you know me? Don't you know that that's an impossibility? That that could never happen? That I'd use all my power to keep something like that from happening? Don't you know that? Kay, now in time, you'll feel differently. You'll be glad I stopped you now. I know that. I know you blame me for losing the baby. Yes. I know what that meant to you. I'll make it up to you, Kay. I swear I'll make it up to you. I'm gonna change. I'll change. I've learned that I have the strength to change. [ed: boilerplate prevent divorce defense] And you'll forget about this miscarriage. And we'll have another child. And we'll go on, you and I. We'll go on.
Kay: Oh, Michael. Michael, you are blind. [ed: Keaton's eyes look so defeated and sad] It wasn't a miscarriage. It was an abortion. [ed: you have to see Pacino's face] An abortion, Michael! Just like our marriage is an abortion. Something that's unholy and evil. I didn't want your son, Michael! [ed: Pacino's silent rage makes him tremble] I wouldn't bring another one of you sons into this world! It was an abortion, Michael! It was a son, Michael! A son! And I had it killed because this must all end! I know now that it's over. I knew it then. There would be no way, Michael... no way you could ever forgive me, not with this Sicilian thing that's been going on for 2,000 years-
[Enraged, Michael lunges at Kay, slapping her across the face. She falls onto the couch]
Michael: BITCH! You won't take my children!
Kay: [sobbing] I will. [ed: mumbled]
Michael: YOU WON'T TAKE MY CHILDREN!
Kay: I will! They're my children too [ed: mumbled]
Here's most of that scene on Youtube.
Looking at the script and scene, we see very clearly that Kay reveals that she killed their son, his son, because she could not take it anymore. After the revelation, Michael slaps her. Michael is forever the calm, cool and business son of the Corleone family. He is the thinker, and he reluctantly kills Salazzo in the first Godfather. This moment of power, one where he is now untouchable, is marred by his wife telling him that his family is broken, and that their marriage was never right, evil. She took away his son. He is told it all by his wife. He reacts in anger and pain, and slaps her. Once. The Wikipedia line above that "he violently stops her, and then she reveals the abortion" is a lie in many ways. She revealed it first. Michael let Kay leave him. He still wore his wedding band. He kept the kids. Did Michael love Kay? I don't know if he ever did. Does he coldly close the door in her face later in the movie when she secretly visited the kids and begged Anthony, their son, for a hug.
It is a cheap shot at a fictional character, but Wikieditors make Michael the abusive husband, and Kay gets a little revenge on him revealing the abortion. In reality, Kay exercises her right to kill a child no matter what the father says, and that was her one defiant act in a relationship and situation in which she felt she was a prisoner. If you ponder if the progressives coordinate, consider the decades involved and subject. We have Wikieditors lying about a movie scene to push a narrative, but there is something else. In the Godfather books, Michael and Kay have two sons and one daughter. There was no abortion. Look at the release date again. Godfather Two came out in 1974. Roe v. Wade was in 1973. Coppola slipped in a topical change to help the little folks at home realize that abortion is a special freedom for women who are trapped in horrible marriages to wealthy, powerful men. The ideology pushing has always been there; it has just become more obvious and zanier. Wikieditors are around decades later to help new generations understand the right way.
One final comment, or thought experiment. Watch this movie or just this scene with even the most vocal mangina of your SWPL friends. Talk to them about it. You are bound to get them to trip up on the reality of abortion or the idea that it is never ever okay to hit a woman. Someone you thought loved you and was committed to a family with you consciously kills your child, your son. How does one react? Thought crime is easier when the socially frowned upon idea is not abstract.