I think gun rights are the least of your worries WHEN this happens (Not if).
We are already building a super highway from Mexico to Canada, that will allow shipping back and forth with no border checks, It's a huge project, approved and underway, and you hardly hear a word about it.
I believe there are people who are trying to implement exactly what you saw on that video.
Will they succeed? Time is on their side. While they keep finding ways to keep us fighting against one another, race, creed, income, country, education and other factors, they slowly build and take control of more and more parts of our life.
You can find out plenty about this from research on the INTERNET.
As it turns out, the INTERNET might be our only way to protect ourselves from this "plan".
Open communications and freedom of exchanging ideas can prevent this.
I don't have my tin foil hat on. Anyone who thinks most of these things aren't happening right now is naive.