Sportsmen are flexing their political muscle around the country, changing laws in state after state to protect against what they see as threats to their heritage.

In Pennsylvania, for example — second to Texas in total licensed hunters — sportsmen have hardly been under siege. Yet even there, the state Constitution could soon carry a new guarantee: “Right of the people to hunt and fish.”

Exactly what that would mean is unclear. But the broader trend is quite clear: Eleven states recognize citizens’ right to hunt, fish or trap, mostly through laws or constitutional changes approved in the last few years.

Six have begun the amendment process, the National Conference of State Legislatures said. No one is even tracking legislation that has not yet come up for a vote.

Many of the changes are attempts to enshrine in law control over practices that sportsmen consider part of their tradition and that animal-rights forces say are immoral.

The wording of the changes, and their impact, varies from state to state.

Restrictions on hunting have succeeded in several states through public ballot initiatives that bypassed the legislature. Pennsylvania has no such option, although even there sportsmen worry that referenda could be legal at some point.

In a world of ever-changing values, lawyer and sportsman Bob Ging pointed largely to an unknown future as reason for special protection. He cited a hypothetical dispute over noise between a gun club and a neighboring development, suggesting that a new “right” might weigh in the sportsmen’s favor.

He also predicted a psychological impact: “The fact that it’s standing there as a constitutional ‘right’ means something.”

Interpretations would be worked out over time by the courts. David Kairys, a constitutional law professor at Temple University Law School, cautioned that “very broadly worded” amendments such as Pennsylvania’s proposed change could have unintended consequences.

“It could get into sprawl, into environment,” Kairys said.

Hunting, trapping and, to a lesser extent, fishing, have been declining for years, as Americans continue migrating from rural areas to cities and suburbs, and as development displaces animals’ habitat.

Those trends, along with evolving ethical beliefs and organized opposition by animal-rights groups, have affected public opinion.