Is it legal in the US to pull out a gun in self-defense, without pulling the trigger, as a response to verbal assault? To minimize the risk of said assault turning actually violent. Let's say I'm being mugged and threatened, or simply feel threatened by someone, and I pull a gun to scare someone to run away, is that okay? It's not like I'd have real intent of shooting someone, unless really attacked.
That's difficult to say for a number of reasons. Does your state or locality require that you attempt to retreat or flee if you feel threatened, or allow you to stand your ground? Can you reasonably prove that you felt your life was threatened if that person leaves and the calls the police and tells them you pulled a gun on them?
Here's how I think of it:
Don't reach for a gun unless you think you're going to have to kill someone.
Don't touch a gun unless you're certain you're going to have to kill someone.
Don't draw your gun unless you're attempting to kill someone.
Aiming your gun at someone is an act of killing.
Pulling the trigger means you've killed them.
Guns are designed to kill, that is there purpose, and law enforcement is going to need to see that that use was justified. So if it doesn't seem like a life or death situation you don't have a reason to draw a gun. If you draw a gun the police are probably going to be called, but if you fire it they're going to be for sure. They're going to scrutinize whatever evidence they find, and that includes verbal recountings from anyone involved or who witnessed what happened. If they don't think that it was a life or death situation, and think that you needlessly escalated it into one by involving a gun, you're going to be in deep shit.
In the unlikely situation that you're being mugged by a random person on the street you're probably best off showing them you have a gun without drawing it. For instance, if it's in your waistband, pulling up your shirt so that they can see it. That way you're not brandishing it, which may or may not be a crime (it's most likely a crime.)
Even that's not optimal though. No one should ever know you're armed. You should never be aggressive with a gun, if the worst happens, like the previously mentioned hypothetical mugger brandishes a knife at you, just pull out your gun and shoot them. Don't give someone who's threatening you any extra opportunity to harm you.
So, you mentioned "verbal assault," which I'm assuming means someone shouting at you "I'm going to kill you." If you believe they intend to kill you don't hesitate, shoot them. If you think it's a bluff or an empty threat, try to leave or deescalate the situation.
Also, since it may not be immediately clear, take note that what the the people who responded to you before me said basically amounted to "don't do that." Their answers are the right answer. Don't do it. Only involve a gun if you absolutely have to, there will be repercussions if you don't actually need to.