Anyone defending this behavior needs to get their mental health examined.
I'm basically the same age as the older son and so much of what he describes sounds very familiar to me. My father would snap and hit my brothers and I. Some examples: once, when I was 10, I was carrying paint for my pine wood derby car and I tripped on the carpet, spilling a small amount of paint onto the carpet. My dad picked me up by my neck slammed me against the wall, while screaming at me. I had bruises on my back for weeks, my mom asked about them but I just made up a story. Other things along those lines, getting my head slammed into my brother's head, then into the wall, kicked in the stomach after being thrown on the floor, smacked hard across the face, punched in the stomach and of course screamed out more times than I could possibly count over the most insane things (I was helping him build something, I was at most 8, and sawdust got into my eye) etc. I was not a troublemaker as a kid, I was very quiet. All of these things occurred when my Mother wasn't home. And we (one of my brothers and I) have only recently told her about it, as well as my wife. Much earlier reports of this story actually lead me to talk about some of it with my wife.
The verbal abuse as a child is why I stopped doing team sports and started running cross country, because out in the trails there were really no spectators, no place for him to be yelling at me. I tried running with him once in middle school (he was a star track athlete in high school, but extremely out of shape by then) and he just made fun of me (I was among the fastest on the team and placed in the top 30 at the state meet). During soccer and basketball games he would yell like a maniac at me and my brothers, even when we were objectively playing very well. There's absolutely no excuse for any of it.
It's especially weird because now I see him these days treat my nephews and nieces, extremely kind and patient, it's a person I never saw growing up.
I suppose it's valuable for public figures to talk about this type of behavior, to show to those that need to hear it, it's not okay and it's not acceptable. And for those who have experienced it to know it's probably helpful to talk someone in your life about it.
Please don't have children if you can't control your temper.