A plane ticket. Others have suggested he’s bored and I concur. IMO, he needs to be intellectually challenged while simultaneously having his fears assuaged. Fear, I believe, is a key driver in pushing people toward fascist ideologies. Most likely he fears not being loved.

Traveling to countries with very different cultures can be both stimulating and reassuring, especially if it involves some significant challenge - a physical one like climbing a significant peak or somewhere that’s just super hard to get to. You can demonstrate that you love and care for him by going with him. Just the two of you.

Why is his political opinion important for a Christmas present? Just give him something he’d like.

Ignore all the joke answers here. It seems insensitive given the subject matter. He’s probably lonely and feeling left out. If he has siblings it’s all the more likely. I was an alienated teenager who was in a place similar to your son I think. I eventually realized I and many others we’re being used to further the agenda of some unsavory fucks who wanted to send us back to the 1860’s. Try to show him how much he means to you. Let him know you care about him. Just don’t drive him away, Show some love and compassion and he’ll realize he’s drinking the kool-aid eventually I think. Hope this helps, good luck!