I don't talk about it with him. He deserves better than what I can honestly tell him.
It'll come up eventually, of course. Then I'll say to him what Steve Earle said at a show I went to during the Bush II years (paraphrase) : "I didn't think that in my fifties I'd have to be a revolutionary, but that's where we are."
And so will he.
The kids need to be in the streets, left and right, conservative and liberal, because they'll be lucky to survive the next few decades, let alone thrive, unless we collectively do a 180 on the way we live our lives. We mortgaged everyone's future and payment has come due.