You know how Dave leaves his Republic after losing the election and goes to Old Olney, right? Well, I got to Old Olney a day or two after he left. I found him dead in that alley decapitated. I could have sworn I found him alive there in my last character.

Is it random if you find him alive or not?

Isn't Old Olney infested by deathclaws? I'd imagine his survival is a matter of luck. When I made him lose the election, I found him dead too.