Not really. I think the incorrect decision was made on a disingenuous argument, one hinged on a subtle, and deliberate error in the reading of the clause. As to whether it's "allowable", I'm not sure what you mean. I'm not yet ready to renounce my citizenship over it. But this week might tilt things in one direction or the other in a 'non-trivial' way.
What I mean by "allowable" is simply that it is one arguable interpretation of the language. I would add, in fact, that this interpretation is suggested by Madison in Federalist #41:
James Madison said:
Some, who have not denied the necessity of the power of taxation, have grounded a very fierce attack against the Constitution, on the language in which it is defined. It has been urged and echoed, that the power "to lay and collect taxes, duties, imposts, and excises, to pay the debts, and provide for the common defense and general welfare of the United States," amounts to an unlimited commission to exercise every power which may be alleged to be necessary for the common defense or general welfare. No stronger proof could be given of the distress under which these writers labor for objections, than their stooping to such a misconstruction.
Had no other enumeration or definition of the powers of the Congress been found in the Constitution, than the general expressions just cited, the authors of the objection might have had some color for it; though it would have been difficult to find a reason for so awkward a form of describing an authority to legislate in all possible cases. A power to destroy the freedom of the press, the trial by jury, or even to regulate the course of descents, or the forms of conveyances, must be very singularly expressed by the terms "to raise money for the general welfare."
Source:
Federalist Papers: FEDERALIST No. 41
Now, observe the implications of Madison's language here. First, he correctly points out that the "general welfare" clause is a modification of the power to tax, and NOT an independent power. That is, it is not a power to "legislate in all possible cases." But second, he does not address at all the lesser claim (which I am making, and which the Supreme Court has validated) that it implies a general power to TAX AND SPEND (but nothing else) for the general welfare. The phrase "to raise money for X" implies, "to raise money TO BE SPENT on X," and that's the phrase Madison uses here -- "to raise money for the general welfare" -- which, as he points out, is a very weird way to get at the power to destroy freedom of the press or trial by jury.
Which is true, of course. The general power to tax and spend for the general welfare is a far more plausible interpretation of the first clause of I:8 than a general power to do whatever the hell it wants for that purpose, which is clearly a wrong interpretation. So why did Madison address the obviously-wrong interpretation, but not the more plausible one (in fact seeming to imply that that is the RIGHT interpretation)?
it seems to me that there are two possible reasons why he structured his argument in this way. One, the anti-federalists weren't raising that as an objection because it didn't concern them. Or two, Madison knew that that particular objection was correct, and so, being a good debater, shifted ground to another related objection which he knew wasn't correct.
Either way, it's pretty clear that the authors of the Federalist believed that the power to tax implied the power to spend (I'm taking it as a given that if Madison believed that, Hamilton for damned sure did). It's true that as president, in support of a veto, Madison once argued differently; however he was not consistent on this in office. After the debacle of the War of 1812, he acquiesced in reestablishing the Bank of the United States, which depended for its constitutional authority on precisely this clause (it was not "necessary and proper" for borrowing money, coining money, or regulating commerce, the only other clauses that have anything to do with it, as we have not always had a national bank).
After that long digression, all I'm saying here is that the first clause does not CLEARLY AND UNEQUIVOCALLY NOT authorize Congress to SPEND as well as tax for the three purposes stated; that this is an allowable interpretation of the English words used, even if the converse -- that your interpretation isn't CLEARLY AND UNEQUIVOCALLY wrong -- is also the case. Do you agree?