Indiana voters will decide next month whether to follow 19 other states in adopting a constitutional amendment to protect the right to hunt and fish.
The measure pits two aggressive lobbies against each other: animal rights activists and the National Rifle Association.
The Humane Society said the proposal is a solution to a problem that doesn't exist.
"The right to hunt and fish are not under attack," said Erin Huang, director of the Indiana chapter of the animal rights group. "We're opening up a pretty sacred document and giving constitutional protection for a pastime that we don't do for other pastimes."
Sen. Brent Steele, R-Bedford, the author of the amendment in Indiana, concedes there is no imminent threat, but said he wants to make sure those rights are preserved.
"It's up to Hoosiers to decide whether this is part of their heritage or not. For me it is, and for the thousands of Hoosiers who hunt and fish, it's an important part of who they are," he said.
Hunting and fishing are popular in Indiana, which has large swaths of forest and many freshwater lakes. The U.S. Fish and Wildlife Service estimates Indiana has about 392,000 hunters and about 801,000 anglers.
Vermont has had the right in its constitution since 1777, but the proliferation of constitutional amendments has occurred over the past 20 years.
Alabama residents approving a constitutional right to hunt and fish in 1996. Minnesota followed in 1998 and North Dakota and Virginia in 2000. More states added amendments between 2003 and 2012, including four in 2012 alone. Arizona rejected a right to hunt amendment in 2010. Kansas also is voting this year on a right to hunt amendment.
Stacey Gordon, a University of Montana associate law professor who wrote a 50-page article on the issue in 2013, said the NRA played a major role in pushing the amendments after 2003, providing a template for lawmakers to pass legislation because some of the early amendments didn't offer much protection.
NRA spokeswoman Catherine Mortensen said the organization got involved because animal rights groups were chipping away at hunting rights. She cited a ban on dove hunting in Michigan approved by voters in 2006 — although the ban had stood for nearly a century until a 2004 law created a limited dove hunting season. She also mentioned a mountain lion hunting ban approved by voters in California in 1990, although such hunting had been outlawed in California since 1972.
"What we're trying to do is be proactive and say we don't want these extremist animal rights groups coming in with a political agenda and chipping away people's right to hunt," she said.
Gordon said hunting opponents would still be able to change the laws, but the amendments make it more difficult. Steele said the Indiana Department of Natural Resources would still be able to set limits to promote wildlife conservation and management.
She also said the amendment could cause problems in some states as some hunters might try to challenge restrictions placed on hunting. She said it depends on the wording of laws and how courts rule.
Chris Niskanen, spokesman for the Department of Natural Resources in Minnesota, one of the first states to pass such an amendment in 1998, said the amendment there has not caused any problem with the agency managing wildlife and courts have agreed with the state's right to regulate hunting and fishing.
The Minnesota Court of Appeals last year ruled that stringent fishing rules imposed on Mille Lacs Lake to try to reverse the decline of the popular lake's walleye population did not violate that state's constitution.