I don’t see that quote; I did read the entire opinion. If you could copy and paste the paragraph it would be helpful.
Congress may also “lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States.” U. S. Const., Art. I, §8, cl. 1. Put simply, Congress may tax and spend. This grant gives the Federal Government considerable influence even in areas where it cannot directly regulate. The Federal Government may enact a tax on an activity that it cannot authorize, forbid, or otherwise control. See, e.g., License Tax Cases, 5 Wall. 462, 471 (1867). And in exercising its spending power, Congress may offer funds to the States, and may condition those offers on compliance with specified conditions. See, e.g., College Savings Bank v. Florida Prepaid Postsecondary Ed. Expense Bd., 527 U. S. 666, 686 (1999) . These offers may well induce the States to adopt policies that the Federal Government itself could not impose. See, e.g., South Dakota v. Dole, 483 U. S. 203–206 (1987) (conditioning federal highway funds on States raising their drinking age to 21).