Wow it sounds like your sister needs a spanking!
I raised 5 kids and the youngest (25) is now a marxist, BLM, antifa lover. Well he says he “understands” them. OK
So you can have good parenting and poof they go off the rails. That’s the part I’m having a hard time with.
PS. They all went to liberal colleges and all graduated, some with 2 degrees. Did that do it? or is it everything, Culture, Music, TV, Movies, Education.....
How do you destroy common sense and logic- <— That is the question.
I take it the other 4 are doing just fine? Then don’t beat up on yourself...many families have a prodigal child.If he is otherwise working and not a deadbeat you did something right. If not...throw his butt out of the house.
When you agree to discuss things with all the BS stripped away, Liberals really don't have a leg to stand on. Try to engage them in a factual, non-emotional, discussion and really do listen to them. Formulate a clear stance of what you see as the shortcomings in what they are saying. After listening to their position, clearly state yours and ask them where they disagree. If you can keep emotions out of the process, it does work.