Is it ignorance or is it a LEO are right, etc...
Human psychology, my friend. Historically people have proven time and time again that they will execute some order no matter how wrong they think that order may be. There are controlled studies and who knows how many actual cases where people rationalized their behavior away because they were told to do something. Sure, Nuremburg is the most recent (and vivid) reminder that being told to do something doesn't exonerate you from your actions...but that only matters if you're on the losing side.
Americans, and perhaps all people but I'll focus on who I am and what I know, have this hubris, this misguided idea that "it can't happen here." we've somehow talked ourselves into beliving that our system and our culture will allow us to prevail in the darkest of hours. It worked before, right? Several times, so it will always work, right?
Maybe I'm too much of a pessimist, but people look at other people and see hope, they see light, they see the good in other people. Well, angels and demons reside within us all. If someone wants pure love, they should get a dog.
With a properly framed argument the most devout American out there would burn the Constitution and then weep later.
By the way, we're all taught this behavior on some level and we've all done this on some level. We've knowingly done something that we shouldn't, but we did anyway for whatever reasons.
We all have angels and demons.