It would be a stunning turnabout if the Supreme Court adopts that view. It would remove some of the most extreme laws from the books -- such as the virtually total ban on handguns in Chicago and some suburban communities. Gun rights advocates would feel sweet vindication.

But there is consolation for the other side as well. The appeals court made clear that a host of other limits on firearms possession are constitutionally permissible. States, it said, could forbid the carrying of concealed handguns, require registration of firearms and mandate training for gun owners.

So if this decision is upheld, it will not change our treatment of guns very much. Complete bans would be off-limits, but they are already rarer than white buffaloes. Most other gun control laws would remain on the books, and anti-gun groups would be free to press for additional ones.

The only obstacle would be the one that has stymied them in the past: insufficient public support. It wasn't the constitutional right to keep and bear arms that induced Congress to let the federal ban on "assault weapons" expire, or that persuaded 40 states to allow the carrying of concealed handguns. Those choices were the product of sentiment among citizens and legislators who see most restrictions on firearms as futile at best and dangerous at worst.

The bad news for gun control advocates is that the Supreme Court may adopt an expansive view of the Second Amendment. The worse news is that's the least of their troubles.