Roberts, C. J., dissenting
gas that is not in transit on the highways.
Rather than grappling with the substance of the tax, the plurality fixates on variations in the time and place of its assessment. The plurality thinks it significant that Washington does not impose the tax at the moment of entry on fuel that enters the State by pipeline or by a barge bound for a refinery, but instead when a tanker truck withdraws the fuel from the refinery or pipeline terminal. This may demonstrate that the tax is not on first possession of fuel in the State, as the plurality stresses, but it hardly demonstrates that the tax is not on possession of fuel at all. Regardless of how fuel enters the State, someone will eventually pay a per-gallon charge for possessing it. Washington simply assesses the fuel tax in each case upon the wholesaler. See 188 Wash. 2d 55, 60, 392 P. 3d 1014, 1016 (2017). This variation does not indicate, as the plurality suggests, that the fuel tax is somehow targeted at highway travel.
The plurality also says that it is bound by the Washington Supreme Court’s references to the tax as an “importation tax” and tax on “the importation of fuel,” ante, at 7 (quoting 188 Wash. 2d, at 67, 69, 392 P. 3d, at 1019, 1020), but these two references to the point at which the tax is assessed are not authoritative constructions of the object of the tax. The state court did not reject Washington’s argument that this is a tax on fuel; instead, like the plurality today, it ignored that argument and concluded that the tax was invalid simply because Washington imposed it while Cougar Den was traveling on the highway. In any event, the state court more often referred to the tax as a “tax on fuels” or “fuel tax[ ].” Id., at 58–61, 392 P. 3d, at 1015–1016.
After the five pages arguing that a tax expressly labeled as on “motor vehicle fuel” is actually a tax on something else, the plurality concludes… it doesn’t matter. As the plurality puts it at page nine of its opinion, “even if” the
