I disagree. The Preamble explicitly states that the Constitution is for these six things. "in Order to" makes it clear what the ends of the document are, and what they’re meant to serve.
That it doesn’t confer unlimited power is orthodox constitutional law. But the Preamble explicitly states the constitutional purposes that should guide the interpretation and exercise of the powers enumerated. And it doesn’t follow that the purposes it states are legally meaningless. The’re part of the constitutional text and inform how the powers actually conferred by the Constitution are construed. As Story commented:
“One of the best established rules of interpretation, one, which common sense and reason forbid us to overlook, is, that when the object of a power is clearly defined by its terms, or avowed in the context, it ought to be construed, so as to obtain the object, and not to defeat it. The circumstance, that so construed the power may be abused, is no answer. All powers may be abused; but are they then to be abridged by those, who are to administer them, or denied to have any operation? If the people frame a constitution, the rulers are to obey it. Neither rulers, nor any other functionaries, much less any private persons, have a right to cripple it, because it is according to their own views inconvenient, or dangerous, unwise or impolitic, of narrow limits, or of wide influence.”
That it doesn’t confer unlimited power is orthodox constitutional law. But the Preamble explicitly states the constitutional purposes that should guide the interpretation and exercise of the powers enumerated. And it doesn’t follow that the purposes it states are legally meaningless. The’re part of the constitutional text and inform how the powers actually conferred by the Constitution are construed. As Story commented:
“One of the best established rules of interpretation, one, which common sense and reason forbid us to overlook, is, that when the object of a power is clearly defined by its terms, or avowed in the context, it ought to be construed, so as to obtain the object, and not to defeat it. The circumstance, that so construed the power may be abused, is no answer. All powers may be abused; but are they then to be abridged by those, who are to administer them, or denied to have any operation? If the people frame a constitution, the rulers are to obey it. Neither rulers, nor any other functionaries, much less any private persons, have a right to cripple it, because it is according to their own views inconvenient, or dangerous, unwise or impolitic, of narrow limits, or of wide influence.”