Of all the political and cultural issues that divide red states from blue ones, none is more volatile than guns and who can carry them.

Conservative rural states like Arizona and West Virginia allow almost anyone to carry a loaded firearm in public, while in urban states and big cities, it can be a felony.

But a piece of legislation quietly churning its way through Congress may change all that by making gun permits more like driver's licenses, transportable across state lines. If you are allowed to carry a concealed weapon in your home state, you would be allowed to carry it in all of them.

The Concealed Carry Reciprocity Act has already sailed through the House of Representatives and has the full support of President Trump. It has roughly 40 co-sponsors in the Senate where a showdown is shaping up between the gun lobby and law enforcement over states' rights and the second amendment.

This is the handgun counter at Van's Sporting Goods outside Jackson, Mississippi, a state with the fourth highest gun fatality rate in the country and some of the weakest gun laws.

Pretty much anyone 18 years of age and not a convicted felon can carry one of these concealed weapons here in their pocket, their pants or their purse for self-defense against muggers, carjackers and other assailants.

If the Concealed Carry Reciprocity Act becomes law, they'll be able to carry them legally across state lines and onto the streets of any city in America.

Tim Schmidt: I think the aim of this bill is to simply allow responsibly armed Americans to-- to be able to travel and-- and-- and continue to defend their families.

Steve Kroft: And carry concealed firearms.

Tim Schmidt: And carry concealed firearms.

Steve Kroft: Anywhere?

Tim Schmidt: Yes. Yes.

Tim Schmidt CBS News

Tim Schmidt is president and founder of the United States Concealed Carry Association. Along with the National Rifle Association and other gun-rights groups, they have successfully sold the bill in conservative red states as a simple, common sense solution to a hodgepodge of confusing, contradictory state laws they say infringe upon Americans' rights to bear arms.

Tim Schmidt: These laws change on a quarterly basis, if not more often. So you can easily go from being a responsibly armed citizen, who's 100 percent legal, to being a criminal just by crossing state lines.

But there is fierce opposition to it in places like California, where there are strict gun laws and concealed carry permits are difficult to obtain. It's one of eight states that generally require thorough background checks, at least some firearms training and a proven need to carry a handgun. In another 30 states, it's easier to get a concealed carry permit and in many of those, there's no requirement to be proficient in the use of firearms. A dozen states have no requirements at all.

Robyn Thomas, the executive director of the Giffords Law Center to Prevent Gun Violence, says forcing states to accept any and all gun permits would make the weakest laws in the country the new norm.

Robyn Thomas: Someone who lives in Nevada, who's able to carry a loaded, concealed weapon in Nevada could now bring that loaded gun into Los Angeles, into San Francisco, and carry their loaded weapon, even though in San Francisco that's not someone who would get a permit.

Steve Kroft: So this law would essentially usurp the gun laws in cities like New York and Chicago and Los Angeles.

Robyn Thomas: Absolutely.

Robyn Thomas CBS News

To blue state liberals who favor gun control, it may sound like a right-wing fantasy but to the National Rifle Association, which contributed $30 million dollars to Donald Trump's presidential campaign and claims credit for his victory, it's their top legislative priority. And with midterm elections this year, nothing is taken for granted. In 2013, a similar bill failed by just three votes.

The NRA declined to give us an interview for this story but its position is well-documented on its website. This is the voice of its leader Wayne LaPierre, right after the last election.

Wayne LaPierre (Soundbite from "Our Time is Now", Date: 12/19/2016): This is our historic moment, to go on offense and defeat the forces that have aligned against our freedom once and for all. I call on Congress and the president-elect to pass national right to carry reciprocity as quickly as it can be written and signed. The individual right to carry a firearm in defense of our lives and our families does not and should not end at any state line.

As proof of injustice, the NRA and other gun rights advocates use the case of Shaneen Allen as ammunition.

In 2013, while driving from Philadelphia to Atlantic City, New Jersey, the single mother and mugging victim was pulled over with a pistol in her purse and a valid concealed carry permit from her home state of Pennsylvania.

Rep. Richard Hudson, House Floor, 12/6/2017: "Let me tell you a story."

Congressman Richard Hudson of North Carolina, who authored the House version of the Concealed Carry Reciprocity Act, told Allen's story on the day the House passed the bill.

Rep. Richard Hudson: What she didn't know is that New Jersey didn't recognize Pennsylvania's concealed carry permit. So this single mom who had never had a run-in with the law spent almost two months in jail and was facing ten years in prison because she'd crossed that state line.

Steve Kroft: How was the case finally adjudicated?

Rep. Richard Hudson: Governor Chris Christie stepped in and pardoned her-- otherwise, like I say, she was facing ten years in prison.

Steve Kroft: How often does that happen?

Rep. Richard Hudson: Well, it-- once is too much. These are law-abiding citizens, these are not the problem.

The large constituency for this message is a long way from the New Jersey Turnpike, in the red states that stretch from the Carolinas through the mountains of the far west. It is the political fault line of regional and cultural differences that split the country and guns are one of the triggers. They're woven into the culture here, passed down from generation to generation in rural, remote parts of the country where dialing 911 does not always bring immediate help. To people here, whether they're single mothers worried about robbers and rapists while driving their kids across state lines to soccer matches, or ranchers worried about rattlesnakes, guns are a security blanket of self-reliance and protection that keep them safe.

Scott Yarbro: For me, it's just a way of life. It's like when I get up in the morning and I get dressed, I get my wallet, I get my watch, I get my keys, I get my phone. It's the same thing to get my gun.

But in most big cities like Los Angeles, Chicago, Washington, D.C. and New York, guns are a cause of fear and concern, not comfort. And law enforcement has lined up against strangers from far away places walking around their cities with loaded guns in violation of their own laws.

Cyrus Vance: I think it would be a disaster for New York City. And I think for major cities around the country.

James O'Neill: I think it's insanity.

Manhattan District Attorney Cyrus Vance and New York City Police Commissioner James O'Neill say their city has the most to lose. Every year, New York takes in nearly 50 million visitors from all over the country into a congested, sometimes chaotic city. Even if a tiny fraction were legally carrying concealed weapons, it would mean hundreds of thousands of additional guns for what is right now the safest big city in America.

Cyrus Vance: You bring that kind of volume of firepower even with well-intentioned people-- it's gonna be extremely dangerous.

Steve Kroft: More guns, more violence. That's what you're saying.

James O'Neill: Absolutely.

They're not just worried about more crime, but an increase in suicides, gun accidents and heated arguments turning into lethal altercations. And with no national database for concealed carry permits, the NYPD says it would not be able to immediately determine whether someone was legally carrying or not.

James O'Neill: Right now we-- we have a good idea of-- of who's carrying guns. If this law passes, the-- all bets are off. Anybody can come into New York City from any state and-- and carry a weapon.

Cyrus Vance: I wouldn't presume to tell the residents of West Virginia what their gun laws should be. They've figured out what they want there. But I don't think they, or Congress, should be having West Virginia's laws put on New York City.

Cyrus Vance at press conference: The people who are strongest against this bill are law enforcement.

Vance and O'Neill have established a formidable coalition of prosecutors and police chiefs from nearly every big city in America to lobby senators to keep the Concealed Carry Reciprocity Act from becoming law.

Manhattan District Attorney Cyrus Vance and New York City Police Commissioner James O'Neill CBS News

Steve Kroft: Representative Hudson, there's huge opposition to this bill, among police departments in major cities in the United States-- Houston. Tucson. Metropolitan DC. Boston. New York City. Baltimore. Seattle. These are all cities where the chief of police has come out against this law. I can-- there are more, if you want me to read more.

Rep. Richard Hudson: Sure. Well, look--

Steve Kroft: Now how do you explain that?

Rep. Richard Hudson: There are folks on both sides of the argument-- and I think good folks on both sides, who are honestly trying to protect their citizens. I just disagree with the conclusions—

Steve Kroft: So you're saying New York or Los Angeles or Chicago big cities have no right to pass any laws that regulate who can carry-- a weapon.

Rep. Richard Hudson: These cities and these states can still continue to have whatever laws they want to protect their citizens.

Steve Kroft: Except they can't have a law that prohibits someone from carrying a concealed weapon?

Rep. Richard Hudson: Right. Just like a driver's license. You can't say you can't drive here --

Steve Kroft: It's not just like a driver's license. Because to get a driver's license, you have to demonstrate a proficiency and-- and establish that you're not going to endanger the public and that you understand all the laws governing it. But that's not the case in terms of possessing--

Rep. Richard Hudson: Right.

Steve Kroft: --getting a concealed carry permit.

Rep. Richard Hudson: But driving is a privilege, owning a firearm is a Constitutionally protected right. So there is a difference.

The central tenet of Concealed Carry Reciprocity is that the Second Amendment gives people the right to carry guns anywhere they want but that idea is more aspiration than factual.

Steve Kroft: Is there such a thing?

Robyn Thomas: Absolutely not. In fact, the Supreme Court has ruled on the Second Amendment in 2008. And what the Supreme Court said is that you have a right to have a handgun in your home for self-defense. And it absolutely does not include a right to carry a loaded, concealed weapon in public. And right up until the Supreme Court says it is your right, that is a fallacy that they're pushing, in the hopes that it will become the truth. But it simply isn't the truth as of right now.

But Tim Schmidt of the U.S. Concealed Carry Association thinks it should be.

Steve Kroft: The Bill of Rights doesn't say that anybody could walk around with a gun in their pocket or a gun in their hostler-- a concealed weapon. It doesn't say that.

Tim Schmidt: Steve, with all due respect, it actually does. It says you have the right to keep and bear arms and it shall not be infringed. Telling me where I can and can't carry a gun, telling me where I can and can't protect my family and loved ones, that's an infringement. Yes, that's gone on for a long time in our country, but we're finally fixing it.

As in almost all political arguments today, each side comes equipped with alternative facts and opposition research, allowing people to believe whatever they want. The NRA claims the only way to stop bad guys with guns is to have more good guys with guns -- it will make people safer…and its facts, as recited by representative Hudson of North Carolina, claim it's working.

Rep. Richard Hudson CBS News

Rep. Richard Hudson: I can tell you that, you know, in the last 20 years, you've seen-- a huge uptick in gun ownership. You've seen a huge uptick in conceal carry permit holders, and at the same time, you see violent crime drop. If you look at the states that have Constitutional carry, you've seen violent crime drop.

Steve Kroft: Are you saying that the more guns that are out there, the safer the population is?

Rep. Richard Hudson: I dunno if I'd go quite that far. But, you know, I'm-- I'm not gonna come out here and say the-- the solution to gun violence is give everyone a gun. But I'm also saying that's not gonna necessarily increase violence.

That conclusion has been refuted by numerous studies, as well as testimony from chiefs of police like Edward Flynn in Milwaukee, who says Wisconsin's six-year experiment with lax concealed carry laws has been a disaster.

Chief Edward Flynn in 2017: Every year since that law was passed in 2011, every year, non-fatal shootings have gone up, gun-related homicides have gone up, and the number of guns seized from the streets by our department has gone up.That's what our cockamamie law has done here.

Steve Kroft: Why is this bill so important to the NRA?

Cyrus Vance: The goal is, of the gun lobby, to have what they call Constitutional Carry, which means that you-- anyone can have a gun, anywhere, anytime. Because the Constitution, and the Second Amendment, in their view, says that. And so the world that they imagine is one where everyone can have a gun. That's not the world that I think I wanna live in. But that's the world that I think they're tryin' to create.

Whether people like it or not, that world already exists in many parts of the country where people are quite happy with it and so are their representatives in Congress. It's expected that just a handful of votes in the U.S. Senate will decide whether it becomes the law of the land.

Produced by Michael Karzis and Vanessa Fica. Associate producer, Ann M. Daly.