Here is the opinion in U.S. v. Coho (D. N.M.), in which the court held that SORNA is constitutional as applied to Indians under both the interstate and Indian commerce clauses acting independently — Coho DCT Order

An excerpt:

Indian Commerce Clause. It is well-settled that Congress has exclusive and plenary authority to regulate matters involving Indians and Indian lands pursuant to the Indian Commerce Clause. See, e.g., Cotton Petroleum Corp. v. New Mexico, 490 U.S. 163, 192, 109 S.Ct. 1698, 104 L.Ed.2d 209 (1989) (“[T]he central function of the Indian Commerce Clause is to provide Congress with plenary power to legislate in the field of Indian affairs.”); United States v. Lara, 541 U.S. 193, 200, 124 S.Ct. 1628, 158 L.Ed.2d 420 (2004) (“[T]he Constitution grants Congress broad general powers to legislate in respect to Indian tribes, powers that we have consistently described as ‘plenary and exclusive.’ ”). This plenary authority permits Congress to enact even criminal laws regulating the conduct of Indians in Indian territory. United States v. Kagama, 18 U.S. 375, 383-84 (1886). Congress has exercised its exclusive jurisdiction in this area by enacting the Indian Major Crimes Act. That Act stipulates that, with respect to offenses committed in Indian Country, FN4 “any Indian who commits against the person or property of another Indian … a felony under Chapter 109A FN5 … shall be subject to the same laws and penalties as to all other persons committing any of the above offenses, within the exclusive jurisdiction of the United States.” 18 U.S.C. § 1153(a). Coho, an Indian, is charged with aggravated sexual assault against Jane Doe, also an Indian, which occurred on the Navajo reservation in Indian Country. The charge against Coho falls squarely within the terms of 18 U.S.C. § 1153(a), and therefore the United States has exclusive jurisdiction over the underlying crime.

The same power that Congress exercised to enact the Indian Major Crimes Act also allows Congress to enact the civil commitment statute of § 4248 at least as applied to Indians who commit crimes in Indian Country. Congress has a protectorate or trust relationship with Indian tribes and possesses broad power to legislate in the tribes’ best interest. The civil commitment statute clearly lies within Congress’ plenary authority to regulate matters involving Indians and Indian land. While the Fourth Circuit recently struck down the civil commitment provisions of § 4248 as unconstitutional when applied to non-Indian defendants, United States v. Comstock, 551 F.3d 274 (4th Cir.2009), it noted that the law may remain constitutional with respect to “persons within exclusive federal jurisdiction (e.g. residents of the District of Columbia and members of the military).” Id. at 278 n. 4. By virtue of the Indian Commerce Clause, Indians belong in the category of persons over which Congress exercises exclusive jurisdiction. For these reasons, I hold that 18 U.S.C. § 4248 is constitutional under the Indian Commerce Clause with respect to this defendant.