During the period between 1968 and 1987, two of the three tribes of Texas- the Ysleta del Sur Pueblo and Alabama-Coushatta- were held under a trust with the state of Texas.
After this relationship was subsequently rendered invalid by the Texas State Constitution, the tribes were transferred under the jurisdiction of the U.S. Government via the Restoration Act.
[1] During this time frame, the Ysleta del Sur Pueblo instituted a process of recreational electronic bingo despite the fact that the state of Texas only permitted the game for matters of Charity.
[5] In addition to this reasoning, Gorsuch turned towards precedent and 'contextual clues' like those of California v. Cabazon Band of Mission Indians where the state could regulate gambling it outright prohibited, but not those that it gives conditions for.
The dissent, written by Chief Justice John Roberts opposed the viewpoint presented in the majority opinion, instead stipulating that a "straightforward reading" made it clear that all gambling prohibited by the state is also barred on tribal land.