1. "Common Sense" - Anything preceded by the phrase "Common Sense" is more often than not, not.
2. Freaking out over Open Carry - It's legal. Get over it. This goes for both anti-gunners and pro-gunners.
3. Caring about Mexico - It was a cesspool before the assault weapons ban, it was a cesspool during the assault weapons ban, and it continued to be a cesspool after the ban sunset. Reinstating the assault weapons ban will not fix a single problem in Mexico.
4. The notion that the Second Amendment is about the National Guard or any other government organized force - The Heller case has been ruled for over a year now and all 9 justices agreed that the Second Amendment is an individual right, not a collective right.
5. "I believe in the Second Amendment, but..." - At that point you should just stop talking, because you're about the render the first half of your sentence irrelevant.