One part ensures states cannot deprive people of "life, liberty, or property, without due process of law." That has been commonly applied by federal courts when it comes to disputes over basic rights, so-called "ordered liberty" cases. Such cases include affirming the right to abortion, and to homosexual sex.

But another rarely used provision also prevents states from depriving the "privileges or immunities" of all citizens. The specific question for the high court in the Chicago case was whether the "immunities and privileges" clause should be used to overturn the handgun ban. An 1873 ruling limited use of that provision when considering a variety of state laws.

All states but Illinois currently allow at least some limited ability to carry a concealed weapon in public, often requiring "good cause" by an individual before a permit is issued. Four states -- Vermont, Arizona, Alaska, and Wyoming -- do not require any permit for a concealed weapon.

After the latest mass shooting event, several congressional lawmakers have promised to introduce tougher gun-control measures in coming weeks. One pending bill is the Fix Guns Check Act, requiring a criminal background check for all gun sales. Such checks are already mandatory for licensed gun dealers, but not for private sellers -- who, supporters of the law say, may sell weapons at guns shows or online without such background checks.

And there have been federal calls for extending the current ban on so-called "assault weapons" to include other types of military-style weapons and those with high-capacity magazines.

As for the Illinois law, its supporters appeared divided -- at least initially in the wake of the appeals court's decision -- on whether they can or should redraft a "concealed carry" law, one that can meet the judicial mandate. One thing is certain: a Supreme Court appeal will come in the next few months, and another potentially history-making test of individual gun rights.

"Today's ruling is a major victory for law-abiding Illinoisans -- and for everyone who understands that the Second Amendment protects the right both to keep arms and to bear arms," said Chris Cox, executive director of NRA's Institute for Legislative Action, just after the 7th Circuit decision last week. "This ruling makes clear that Illinois cannot deny law-abiding residents the right to carry a firearm for self-defense outside the home. This is a step in the right direction for all gun owners. We know it probably won't be the end of this case, and we're ready to keep fighting until the courts fully protect the entire Second Amendment."

Gun control is one of those hot-button social issues that stirs energies on competing sides. The rhetoric naturally becomes more heated -- and personal -- in the raw aftermath of events like the shootings in Newtown.

The impact of rulings from the Supreme Courts and lower court judges acting in their mandate always come with lingering reminders of these kinds of tragedies from across the nation, as local communities wrestle with whether banning often the cheapest, most commonly available kinds of firearms will reduce violent crime or leave honest citizens vulnerable.

The Illinois concealed carry ruling is Moore v. Madigan (12-1269).