The Bureau of Indian Affairs is expected to issue a decision, possibly in a matter of weeks, modifying if not altogether scrapping Bush-era rules that made it all but impossible for tribes to open new, off-reservation casinos, industry observers say.

But the pending decision, which could potentially make it easier for tribes to open new gambling venues hundreds of miles away from their home reservations, has drawn the ire of a group of powerful US senators.

Led by US Senate Majority Leader Harry Reid, the group of senators from western states recently wrote to the Interior Secretary Ken Salazar to protest any loosening of restrictions on off-reservation casinos.

Meanwhile, the intensifying battle over off-reservation gambling could complicate efforts by the Indian gaming industry to reverse a devastating Supreme Court decision.

Tribal casino lobbyists are seeking congressional help to ‘fix’ the so-called Carcieri decision, a sweeping ruling that threatens to shut down a range of new tribal casino proposals, even those that are on traditional reservation land.

But it comes amid rising anger in Congress over the expansion of Indian gaming.

“As you know, we strongly opposed taking off-reservation lands into trust for gaming purposes,” writes Reid and four other senators.

Given the trouble brewing in Congress, there is not likely to be an outright scrapping of the Bush restrictions, which barred new off-reservation casinos if they were more than 40 miles from a tribe’s home base, said Professor Kathryn Rand, co-director of the Institute for the Study of Tribal Gaming Law and Policy at the University of North Dakota.

She predicts a more muted revision, one that will make distance just one of a number of factors to be considered.

“It is still a political hot potato. The presidential election did not change the controversy over Indian gaming, especially the controversy over off-reservation casinos,” Rand said.

However, Rand believes the battle is based more on politics and perception, with off-reservation casinos representing just small part of the overall growth of Indian gaming.

All told, tribes have opened nearly 400 gambling venues since the passage of the landmark Indian Gaming Regulatory Act in the 1980s.

There are now roughly 20 proposals by tribes to open new, off-reservation casinos.

“A relatively few number of tribes have succeeded in opening off-reservation casinos,” Rand notes. “The restrictions already in place are already operating as constraints. Obviously, not everyone agrees with me.”

Yet while the numbers may not be large, examples of tribes seeking to open new casinos – sometimes hundreds of miles from their traditional reservations - has stirred anger.

The backlash has not just been from local officials, but also some Indian nations concerned about other tribes invading their competitive territory with new casino proposals.

“The casino industry, many blue Democrats, most Republicans and above all the unions are against expanded Native American gambling,” writes Reverend Richard McGowan, an economist and gaming industry expert at Boston College.

A big question now is whether fallout over the off-reservation casino issue – and the emergence of Reid as a key critic - will derail the Indian casino industry’s push to revise an even more devastating Supreme Court ruling.

Under the Carcieri decision earlier this year, the high court ruled that tribes not recognised by the federal government before 1934 cannot create new, federally-sanctioned reservation land.

This practice, called taking land into trust, is a basic requirement for tribes looking to open a casino.

The ruling has meant that even tribes looking to open casinos, even if they are on their main reservations – such as the Mashpee Wampanoag tribe in Massachusetts – are prohibited from doing so if they were not recognised until after 1934.

U.S. Senator Byron Dorgan has filed legislation that would amend the act so that tribes recognised in recent decades would enjoy the same rights.

The political leverage of the Indian gaming industry should not be discounted, argued William Thompson, a professor and gaming industry expert at the University of Nevada Las Vegas.

“I equate them with the AARP and the National Rifle Association,” he said.

But congressional critics of off-reservation gaming are threatening to force new restrictions on off-reservation gambling into any bill that attempts to deal with the Carcieri decision.

In their letter, Reid and his fellow Western senators hint of possible legislative action.

If current regulations or rules are not adequate to deal with off-reservation gambling, the senators make clear they are ready to step in with legislation.

“Please advise us as to your solution and whether legislation is necessary to affect policies supporting these principles,’’ the senators write to Salazar, the Interior Secretary.