U.S. House Bill 308 and Senate Bill 152 would bar the Tohono O’odham Nation from building a casino on their trust land in the Phoenix suburb of Glendale. Last week Navajo lawmakers voted 18-0 to support the bill called the “Keep the Promise Act”.

The Navajo Nation has a casino about 160 miles from the development and they consider a new casino in the area to be a threat to their revenues. Navajo Nation Council Delegate Alton Joe Shepherd said, “We are protecting our nation’s investment in gaming and also protecting the image and reputation of Arizona gaming tribes as it relates to current compacts with the state.”

Navajo Nation Council Speaker LoRenzo Bates said, “The Keep the Promise Act will help to protect Navajo’s investment in the Twin Arrows Navajo Casino Resort and protect the integrity of Arizona’s compact.”

The West Valley Resort casino is currently under construction as Tohono O’odham fend off various threats to their enterprise. Other tribes as well as the the Glendale City Council in the area have spent millions of dollars on lawsuits and lobbying to put a stop to the development. Glendale has spent as much as $5 million on their effort. The Gila River Indian Community has spent nearly $11 million lobbying congress. Senator John McCain reintroduced the Keep the Promise Act of 2015 in January, legislation which would prohibit the construction of any new Indian gaming operation on unincorporated land in the metro Phoenix area that is not contiguous to an existing Indian reservation. The House Natural Resources Committee and the Senate Indian Affairs Committee have both endorsed the bill which could appear on the calendar of either house of congress at any time.

Thursday’s vote by the Navajos represents their first foray into the melee.

Lawmakers may be biting off more than they want to chew if the bill is passed however as the Tohono O’odham Nation would suffer enormous financial losses if their project is made illegal and would almost certainly redress the government for damages. The Congressional Budget Office has estimated that damages may be in the area of a billion dollars or more if  the tribe is denied use of it’s lands held in trust by the U.S. Government.