You hear it all the time right now.
"Gays are causing the destruction of the world."
"Transgender people are freaks."
"Muslims are evil."
"Republicans are heartless."
I can go on. But it all pretty much comes down to one thing. "WE have a problem with THEM".
And that is a major reason why this is all able to continue so strongly. While we talk about the world being global and everyone is connected, it is actually very VERY easy to inadvertently use those same connections to find others who think exactly the same as you do, and create a web of isolation. And that is what has happened. These are all people who have isolated themselves from certain aspects of the world and don't really know any of the people about whom they are talking. "But I argue with them all the time!" If you are arguing, you are still isolating. You are setting up a strong US camp to fortify yourself against the THEM camp. You still don't know them.
I am not preaching here. This is actually a psychological feature that has come under a lot of study recently with some startling truths coming out. Most "hate" groups have never actually met anyone they are opposing, at best only fought them. Most groups that are being hated are too afraid (understandably) to meet their haters, instead only struggling to get by in a world with them. This continues the Us/Them dichotomy.
When two groups get to meet, as equals, such as just a neighbor that you never realized was part of the group you hate or as a co-worker that you team up with on a project, an amazing thing happens.
Minds are changed.
People are understood.
They all become Us.
This is called Contact Theory. It is surprisingly complicated, but it can be broken down into a simple thought - We need to know them, and they need to know us.
Below is an example of a success story. It was not a perfect moment of Contact (which as I a said, is surprisingly complicated or else we could all just do it tomorrow), but it is a good one. There are other stories like this out there.
I just wanted you all to know that all those horrible stories you read out there, and all those horrible things you think about "those" people, well, there is actually a way that we can get past it. We just have to not be afraid of meeting THEM*.
* Unless THEM happens to be giant radioactive ants.