That is correct. When Montana entered into statehood the state signed a contract with the feds. Part of the contract was for the right of any individual to own firearms. Sounds like Montana real estate may shoot through the roof if the Supreme Court rules the wrong way.
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That's the issue at hand in a pending U.S.Supreme Court case originating in the District of Columbia, where authorities have banned handguns under the claim that such a limit is "reasonable" and therefore enforceable even given the rights listed by the 2nd Amendment.
The Montana contract is archived as Article I of the Montana Constitution. At the time the then-territory's "Compact with the United States" was agreed to by Congress, the Montana Constitution included the "right of 'any person' to bear arms," the group said.
In a joint resolution from the Montana leaders, including Congressman Denny Rehberg, they caution that should the Supreme Court decide to change the U.S. interpretation of the 2nd Amendment and allow those rights to apply only collectively, it would violate the contract under which Montana entered the union as a state.
"The Montana Resolution cautions that a collective rights decision would violate the Montana contract for statehood because when that contract was entered the collective rights interpretation had not yet been invented and the individual rights view was an accepted part of the contract," an announcement from the leaders said.
"A collective rights decision in [the pending court case] Heller would not only violate Montana's contract for statehood, but also Montana's customs, culture and heritage. We hope the Supreme Court will recognize and credit the contract argument, an argument unmentioned in any of the briefs submitted in the Heller case," said Gary Marbut, the president of the Montana Shooting Sports Association.