Parents side with kids against school officials more often. School shootings increase.
By that I don't think parents siding with their children is in any way new, so a correlation wouldn't even exist.
I grew up knowing that if I got in trouble at school I was going to be in trouble at home. I figured this was a common approach in my day.
I don't know if I'd agree that it's ever been one way over the other.
If I got in trouble in school I'd get in trouble at home. I think it's just a parenting choice, and I don't think it's changed all that much.
I've just seen no real evidence one way or the other.