The upcoming arguments before the 9th U.S. Circuit Court of Appeals this spring over whether the Shoshone-Bannocks can use video gambling machines is one of multiple fronts in the battle over tribal casinos in Idaho.

Republican legislative leaders also plan a separate challenge to the constitutionality of a 2002 voter initiative that authorized casino-style gambling by Indian tribes.

Tribal officials say Idaho's challenges are part of a national campaign by states to clamp down on the growth of Indian gaming, which last year raked in $20 billion, including $1.8 billion from the 44 Indian gaming operations in Idaho, Oregon, Washington and Alaska, which is limited to tribal bingo halls and pull-tab shops.

"No one dreamed this industry would mature as quickly as it did," said William Bacon, an attorney with the Shoshone-Bannocks. "The states are now putting pressure on the feds to either allow them to get a share of the money or to rein this situation in."

Some state legislators complain that the video gambling machines on Idaho reservations are merely electronic versions of the slot machines banned in the state constitution. They also worry that pressure to expand existing casinos to off-reservation locations is growing.

"This is what we feared would happen," said Rep. Maxine Bell, R-Jerome, part of an anti-gambling group. "It will always be an issue with those of us who do not want the state to be made into a gambling Mecca."

The growth of Idaho's Indian casinos has been limited to operations on reservation land in Fort Hall, Worley, Lapwai, Kamiah and Bonners Ferry. The Shoshone-Bannocks' plan for a new casino in Twin Falls, Mountain Home or near Boise was the first off-reservation casino proposed since then-Gov. Phil Batt rejected the Coeur d'Alene Tribe's plan for a casino in Post Falls nearly a decade ago.

Under federal Indian gaming laws, tribes may open casinos outside reservation boundaries