In the national gun control debate, Vice President Joe Biden is viewed as the Democratic party's point man on strengthening the limits of firearm ownership.
In an online town-hall Q&A this week, Biden was bombarded by people skeptical of his efforts to ban assault weapons and high capacity magazines.
One participant asked Biden how he and President Barack Obama reconciled a ban on assault weapons with those already in the hands of criminals.
"How can say this politely?" Biden said. "The Constitution does allow the government to conclude there are certain types of weapons that no one can legally known."