Thus, even though the tax laws in question had been declared unconstitutional, the taxpayers effectively did not receive any repayments; rather, the amounts due back to them from the States were taxed by the Commonwealth. The Commonwealth would then repay these amounts to the States, with the result that the States were not in any financial disadvantage.
This passage describes a scenario where a tax law was declared unconstitutional but the taxpayers did not receive any refunds. Instead, the amounts owed to them by the states were taxed by the Commonwealth and then repaid to the states, leaving no financial disadvantage for the states.