The Oklahoma City Thunder joined more than two dozen businesses, public universities and law enforcement groups Wednesday in opposing firearms bills that would allow most adults to openly carry guns without training or background checks.

The groups sent a letter to Senate President Prop Tempore Brian Bingman urging him to halt the two bills. One of them passed late Wednesday on a 37-9 vote.

The “constitutional-carry” bill would allow Oklahoma adults over 21 without a felony conviction to openly carry guns without a license, training or background checks. Those who wished to carry concealed would still be required to obtain a license.

The bill is now scheduled to go to a conference committee for possible changes before it is considered again in the House and Senate.

The groups’ letter expressed concern that the measures could jeopardize existing gun bans by private businesses, at public colleges and universities and at public events hosted at public parks or fairgrounds.

"Until these issues can be addressed, we ask that these measures not move forward in the Senate," the letter states.

Sen. David Holt, R-Oklahoma City, said the measures could have unforeseen consequences should it make it on the November ballot.

“History will show you that about 70 percent of the laws that have even been subjected to this legal standard have been thrown out as unconstitutional,” Holt told KOKH-TV.

Sen. Nathan Dahm, R-Broken Arrow, the author of the bill, has insisted that any existing bans on firearms would remain in place. But despite his reassurances, Holt is still concerned that the ban of firearms at places like the Chesapeake Area, where the Thunder play, would be thrown out as well.

"The NBA, for example, does not allow guns in their games. If that got flipped on its head and suddenly guns had to be in the arena, if you wanted to bring your gun, the government could not stop you from bringing your gun, that would be very problematic, that would ultimately cause the Thunder to leave," he added.

Meanwhile, the National Rifle Association is mobilizing its members to support the proposed constitutional amendment.

The resolution seeks a public vote on whether to amend the Oklahoma Constitution to make it more difficult for the Legislature to regulate firearms and to prohibit laws requiring registration or special taxation of firearms or ammunition.

"This resolution would allow Oklahomans to strengthen the state constitutional protections for gun rights," said NRA spokeswoman Catherine Mortensen. "This improved amendment would make it crystal clear that Oklahomans have the right to use a firearm for personal defense, hunting, and recreational shooting."

Mortensen says similar constitutional amendments have been enacted in Alabama, Louisiana and Missouri, but a similar measure brought up in Texas last year was derailed after opposition from the business and law enforcement communities.

Under current Oklahoma law, residents wishing to carry a firearm openly or concealed in public must obtain a gun license that includes a criminal and mental health background check and some firearms training.

The Associated Press contributed to this report.

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