I'd make a comment the first time Facebook friends posted a hateful trans/homophobic or racist meme, then message them privately and ask them not to do it again.
If they did it again, I'd tell them in a private message that I found such posts offensive and that I would have to defriend them. Invariably..even with my closest friends from college..the person would mock me and make sneering racist/trans/homophobic comment, so I'd defriend them.
In a couple of months, my Facebook page was a great deal quieter and there were more photos of baby ducks and kittens.
I also used to try to engage the Trumpites, but found that they don't care about facts, or the damage they cause. Straight, white and might is right-or they fight!