Well, you and I know that isn't true, but that line has existed for decades now. Except, when I've heard it, the word "Obama" has been replaced with various groups. So, where X=the group currently about to come for the guns, the phrase goes, "X is coming for/wants to take away your guns."
I'm just as tired of hearing this as everyone else who knows better, so I have a plan for the next time I hear it.
The next time you're treated to the "x is coming for my guns" phrase, you shouldn't be exasperated. Instead, it's game time! It's time to make it work for you!
Tell that person that you belong to Group X and, as a member in good standing, you have a schedule of when they're coming to get that person's guns. But since you belong to Group X, you have no morals, and no qualms about sabotaging the agenda of your own group to make a buck.
So, tell them that for the right price you'll tell them when Group X is coming for their guns. Surely they'll believe you. They HAVE to believe you, or else their own argument falls apart.
The day comes, you tell them to be somewhere else with their guns. The day comes and goes, they still have their guns, contract fulfilled. Just make sure you get paid first, and that person never finds out where you live. In fact, make sure you know where they live. If you need it, just ask for their name, look inside of a binder (it can be filled with blank sheets of paper), ask them if they're, say, John Smith of 123 Main Street. They'll usually respond with the correct address, you say "Ah," and look back over your "schedule" and give them a date that works for you.
When the scam is complete, make sure you tell your target that, since he wasn't home, they'll return later. But you know when that day will be too. You can grift him over and over.
Just like the NRA.
And if you want to get rid of this person, you might talk him into moving away permanently by telling him that they'll never leave you alone, but there's an island of "sanity" where Group X just can't go, because there are too many gun owners there and taking away the guns is impossible because the Patriots (TM) that live there are just too well armed. Then make something up, just make sure it's believable. Your target isn't likely to move to San Francisco . You'll have to make him and his Liberty Projectiles (TM) move somewhere like, say, Little Rock.
If the scam works then you've got their money. If your target sees through the ruse, then he isn't likely to have used that phrase in the first place. Or your target has to admit that the phrase is bunk. Either way, you win.