And starting in early 2016, I would go home to visit, and my dad - he doesn't agitate easily, but he was so agitated. All he wanted to do was talk about Trump and what he was seeing happening. He was really nervous. It was almost visceral - like, he was reliving the past. Every time I'd go home, he was just, like, "Please tell me Trump's not going to win." And I would tell him, "Dad, Trump is not going to win." And he's just, like, "I don't believe you; I saw this once before. And I'm seeing it again, and the Republicans, they're just falling in lockstep behind him." He was so nervous.

I remember saying: "Dad, what's really different about America today from Germany in the 1930s is that our democracy is really strong. Our institutions are strong. So, even if you had a Trump come into power, the institutions would hold strong." Of course, then Trump won. We would have these conversations where my dad would draw all these parallels. The brownshirts and the attacks on the media and the attacks on education and on books. And he's just, like, I'm seeing it. I'm seeing it all again here. And that's really what shook me out of my complacency, that here was this man who is very well-educated and astute, and he was shaking with fear. And I was like, Am I being naïve to think that we're different?

That's when I started to follow the data. And then, watching what happened to the Republican Party really was the bigger surprise - that, wow, they're doubling down on this almost white supremacist strategy. That's a losing strategy in a democracy. So why would they do that? OK, it's worked for them since the '60s and '70s, but you can't turn back demographics. And then I was like, Oh my gosh. The only way this is a winning strategy is if you begin to weaken the institutions; this is the pattern we see in other countries. And, as an American citizen I'm like, these two factors are emerging here, and people don't know.

So I gave a talk at UCSD about this - and it was a complete bomb. Not only did it fall flat, but people were hostile. You know, How dare you say this? This is not going to happen. This is fearmongering. I remember leaving just really despondent, thinking: Wow, I was so naïve to think that, if it's true, and if it's based on hard evidence, people will be receptive to it. You know, how do you get the message across if people don't want to hear it? If they're not ready for it.

I didn't do a great job framing it initially, that when people think about civil war, they think about the first civil war. And in their mind, that's what a second one would look like. And, of course, that's not the case at all. So part of it was just helping people conceptualize what a 21st-century civil war against a really powerful government might look like.

After Jan. 6 of last year, people were asking me, "Aren't you horrified?" "Isn't this terrible?" "What do you think?" And, first of all, I wasn't surprised, right? People who study this, we've been seeing these groups have been around now for over 10 years. They've been growing. I know that they're training. They've been in the shadows, but we know about them. I wasn't surprised.