"In 1972, 90% of Americans identified as Christian. By 2020, that number was down to 64%."

Just because someone "identifies" as Christian does not mean they actually try to follow Christ in their lives. After all there were a lot of "Christians" in the US in the 1700s and 1800s (including some of our Founding Fathers) who thought chattel slavery was just fine. There are a lot of "Christians" today who think racial discrimination is just fine.