* Disparities in state gun laws increase since Newtown
* States with strict laws worry about guns from elsewhere
* In Washington, push for gun laws likely to be watered down
While Washington politicians battle over new gun-control measures, state legislators have already passed dozens of new firearms laws since the Newtown school massacre ignited a national debate in December.
The new state laws, a small fraction of the 1,500 or so gun-related bills that have been proposed at state level, reflect the vast political and ideological differences in the debate over gun rights - a gulf that helps explain why lawmakers in Washington find it so difficult to reach a consensus on the issue.
Several Democrat-controlled states have tightened their already tough gun laws, while a dozen Republican-leaning states have loosened the few restrictions they have on the constitutional right to bear arms.
The net effect has been to increase the disparities in the nation's patchwork of gun laws, and widen the divide between urban areas where gun ownership is viewed with suspicion and rural regions where guns are firmly embedded in the culture.
In New York, a new law authorizes police to track ammunition sales and prevents gun owners from buying ammunition magazines that hold more than seven bullets.
Under a new Maryland law, gun buyers will have to be fingerprinted and licensed. In Connecticut, where the massacre of 20 young children and six teachers at Sandy Hook Elementary School in Newtown inspired the gun-control legislation now before the U.S. Senate, those who own high-capacity magazines will have to register with the state.
In many southern and western states, however, legislators are moving in the opposite direction.
Arkansas now allows guns in churches, bars and liquor stores. A new law in Wyoming allows judges to carry guns in their courtrooms. South Dakota school administrators will be able to arm teachers.
State legislators have introduced more than 1,500 gun-related bills since January, according to the Sunlight Foundation. Roughly half of these new proposals would strengthen gun laws, while the other half would weaken them, the nonprofit group found. Of those, around 50 have been enacted into law.
Because weapons can be easily carried across state lines, states that try to impose tight controls on gun purchases can be undercut by other states that are more permissive, analysts say.
"There's no metal detectors at the borders," said Northeastern University criminologist James Alan Fox. "Any state's ability to deal with the gun problem is limited by that fact: They're not isolated islands."
Gun-control advocates say that's one reason Congress needs to strengthen federal background checks of prospective gun buyers, limit the size of magazine clips and ban military-style "assault" weapons.
"State legislatures that enact irresponsible laws truly do put lives at risk not just in their own state but in neighboring states as well," said Laura Cutilletta of the Law Center to Prevent Gun Violence.
Gun-rights activists say states are rightly fulfilling their roles as "laboratories of democracy," allowing policymakers to see what approaches work and what doesn't. They say the differences in laws also mean that gun owners can move to states with expansive gun rights, if they wish.
"I think diversity is good," said Joseph Tartaro, president of the Second Amendment Foundation. "From a personal liberty standpoint, any time you have more options you're better off."
FEDERAL LAWS FACE TOUGH OPPOSITION
The Second Amendment of the U.S. Constitution guarantees the right of individuals to own firearms, but courts have ruled that right is not unlimited even as they have struck down some of the most restrictive laws, such as the District of Columbia's handgun ban.
In Washington, gun-control advocates scored a victory on Thursday when the Senate began debate on new gun control legislation. But measures that enjoy broad public support - such as an expanded background check system that would include sales made online and at gun shows - could be weakened or made unpalatable to many lawmakers during the weeks of debate coming up in the Senate.
Even if they clear the Senate, such proposals face a more difficult path in the Republican-controlled House of Representatives.
Other measures, such as an assault weapons ban and limits on large-capacity magazines, are widely seen as unlikely to pass either chamber.
Gun-control advocates say that whatever happens in Congress, the action at the state level shows that momentum is on their side.
While many of the pro-gun laws that have passed so far have been incremental expansions of rights that already exist, the new laws in Colorado, New York, Maryland and Connecticut would impose major new restrictions.
"We're hopeful that the rest of the country will follow our lead, both for their sake and our sake," said Vincent DeMarco, president of Marylanders to Prevent Gun Violence, who pushed for his state's new requirement to fingerprint and license handgun buyers.
Gun-control advocates also point to gains in states where they traditionally have had little success.
In Alabama, the governor vetoed a bill that would have allowed armed volunteers in schools. Legislation that would have allowed college students to carry guns on campus fell short in Republican-controlled Georgia.
In gun-friendly Montana, the governor vetoed a bill that would have nullified federal firearms laws in the state. And in Utah, one of the most solidly Republican states in the country, the governor vetoed a bill that would have allowed gun owners to carry concealed weapons without a permit.
On the other side of the ledger, broad gun-control bills fell short in Illinois and Minnesota, states with Democratic governors and Democrat-controlled legislatures.
Richard Feldman, a former National Rifle Association lobbyist who now heads the Independent Firearm Owners Association, said one-third of the U.S. population now lives in states with gun laws that his groups sees as restrictive. That could spur a backlash among gun owners, he said.
"As an advocacy group working those states, it makes my job much easier because people realize how tenuous their rights are," he said.