Under such an interpretation of the amendment, his point holds. The motivations for granting a right do not affect a right so granted, even if others use that right despite having other motivations. It may be something that we should bear in mind when discussing that right, but the motivation cannot be arbitrarily applied in order to remove the right.
How exactly is that going to be enforced? Inspect people's homes?
We require documentation demonstrating safe-storage for handguns here. It's not that odd.
Then again, you can't have an abortion here. I am that rare European who acknowledges the significance of the American defence of and emphasis on rights, especially as expressed by the U.S. constitution. I have asked my friends if they would rather people had the right to bear arms and to have an abortion, or didn't have the right to bear arms or to have an abortion. It's a question that typically produces silence.
A lot of you will no-doubt say "I'm a European, and we can have abortions and don't have guns everywhere! False dichotomy!"
But take the long view. We are lucky enough to live in this Europe, at this time. But the fact is, our constitutions, institutions, and traditions have repeatedly been shown to be inadequate. Europe's most republican nation, France, is on its fifth republic, with a couple of empires in between. Most of western Europe was liberated in 1944-1945 by a constitutional democracy that has existed since 1776.
In short, it's easy to bash Americans. But whilst (in my opinion) they currently suck ass at political practices, they are much better at enshrining and acknowledging political rights. I always feel that Europe is one bad bureaucracy away from a good one.
It really hasn't been that long, folks.