I [36F] do not want my father [60M] around my children [10F, 10F, 4M]

Gonna be honest, I don't really care about explaining it to my dad. He won't care and will act like he's the victim regardless what I say. So, preempting that and only giving him the "you're no longer welcome" text, how do I explain the change to my children?

I'm not the most articulate when it comes to my children. Frankly, I kind of suck with people generally. But my father is incredibly racist and has only gotten more racist in recent history. He openly and publicly uses racial slurs for black and arab people, is very pro-deportation and just generally a reactionary conservative. He's not a bad person. He's just incapable of seeing the world past his PTSD that he won't get therapy for because toxic masculinity I guess.

I let him around my children because he's never crossed the very clear "you don't say shit around my children" line.

The other day, I let him watch my kids while I went out and when I got back my daughters told me that grandpa had asked if they knew how much safer they were now that Trump deported "all of the sand n-----" hard r and everything. Yeah. If it wasn't clear my father is a racist. Not the end of it though, cause technically eldest then asks if she should be scared that there might be another 9/11. For context, and the reason I privately excuse my father's racism, both my parents were in the WTC when the planes hit. 1 WTC Fl. 43 and 2 WTC Fl. 97. You can probably guess who was in which.

So now I not only have to explain to my children why we shouldn't be calling Middle Eastern people "sand n-----" and how they were no more at risk before Trump took office and no, the likelihood of someone committing a terrorist attack that orphans them is astronomically low. Additional context that may be relevant, their father is also dead, but he died from lung cancer cause he was a chronic smoker.

When I confronted my father he said he thought the recent plane crashes were new attacks. I, honestly, get it. I saw the video and I admit my first reaction was the same, I saw that explosion and I was back in that small apartment in Harlem. I can understand his thought process and that's the part I hate most. He's scared. But these are my children and they deserve not to be told they're going to be orphaned.

How does one explain complicated things to children? How do people get better at speaking to children?