California has sovereign authority to tax Indians resident within its borders who do not live on reservations. IGRA does not impliedly preempt the tax because the tax does not interfere with the Tribe’s gaming operation or Congress’ purpose of ensuring that the Tribe is the primary beneficiary of its gaming operation. (Mot. 8-13.) Further, the tax does not interfere with Tribal self-governance because it impacts only members living offreservation and does not substantially affect essential governmental functions.