The ranks of gun owners with approved concealed carry permits has swollen to 17 million, and new legislation offered in the Senate Thursday would make it easier for them to carry their weapons across state lines.

Bolstered by a larger pro-gun caucus in the Senate, Texas Republican Sen. John Cornyn is introducing his latest version of the Constitutional Concealed Carry Reciprocity Act.

"This bill focuses on two of our country’s most fundamental constitutional protections -- the Second Amendment’s right of citizens to keep and bear arms and the Tenth Amendment’s right of states to make laws best-suited for their residents," said Cornyn, a top Senate GOP leader.

"I look forward to working with my colleagues to advance this important legislation for law-abiding gun owners nationwide," he added.

He already has 31 co-sponsors.

North Carolina Rep. Richard Hudson has introduced parallel legislation in the House.

All states allow some form of concealed carry, though the rules are very different. What's more even those who allow their citizens to carry pistols do not always allow non-residents to carry even if they have permits.

Cornyn's plan would grant reciprocity while still keeping intact state prohibitions on those not allowed to have gun permits.

The National Rifle Association's Institute for Legislative Action was quick to endorse the legislation.

"The current patchwork of state and local gun laws is confusing and can cause the most conscientious gun owner to unknowingly run afoul of the law when they are traveling or temporarily living away from home," said Chris W. Cox, executive director of the NRA-ILA.

"Law-abiding citizens should be able to exercise their fundamental right to self-defense while traveling across state lines. We thank Senator Cornyn for his leadership on this important issue," Cox added.

Tim Schmidt, president and founder of U.S. Concealed Carry Association, also had praise. He told Secrets, "Personal defense is a natural born right of free people that is affirmed by the 2nd Amendment of the U.S. Constitution. Senator Cornyn understands that a civil liberty like this should never stop at a state line."

The legislation has a strong backer in Donald Trump Jr. and picked up strong Senate support last year. The new Democratic-controlled House, however, appears to be moving in a distinctively anti-gun direction.

Some 22 states already allow concealed carry reciprocity.

And it's not just gun fans who want the right to carry across state lines.

The NRA made the point that often first responders are caught up in the rules. They said, "The consequence is obvious, as otherwise law-abiding citizens – specifically veterans, single mothers, disaster response workers, nurses, medical school students, and even corrections officers – have wrongfully suffered seizure of property, arrest, detention and even prosecution because they failed to navigate the legal minefield that is the current state reciprocity system."

Gun Owners of America added, "Sen. Cornyn's bill would allow citizens to protect themselves and their families while traveling across the country — clarifying a confusing patchwork of state laws. An infamous case of such a mix-up was Shaneen Allen, a Pennsylvania concealed carrier who made a wrong turn into New Jersey and then was imprisoned for over a month simply for possessing a firearm that was lawful in her home state."

Cornyn said his plan treats carry permits like a state-issued drivers' license.

He highlighted these points in his bill:

