Okay, so first, we have the power of the judiciary to hold that a statute is unconstitutional. In that regard, do you agree with the Supreme Court's claim in Marbury v. Madison (1803) that the Court has that power?
Second, we have the power of the President to veto the legislation and, at a minimum, delay the Congress by requiring that it pass the legislation with a super-majority.
Third, we have the power of the people to elect to the Congress and the presidency persons who will respect the views of the people regarding the appropriate boundaries of Congressional power.
Assuming that you accept the propriety of judicial review, how should the Supreme Court actually review a statute like the one we were discussing which suspended the use of literacy tests? Congress was authorized to suspend the literacy tests because they were being used by certain states to deny or abridge the right of black citizens to vote. Did the Court actually make that factual finding itself - that the literacy tests were in fact being used to discriminate against blacks? Or did the Court just accept that fact as accurate because Congress declared that Congress had found that fact to be true? Should the Court just accept the accuracy of Congressional findings? As a practical matter, does it have any choice? How could the Court independently determine the accuracy of Congressional findings?
These turn out to be the pivotal questions in terms of whether or not the Supreme Court can impose meaningful internal limitations on the legislation of Congress. If the Court cannot find sensible means by which it can review the accuracy of Congressional findings, the Court's role, as a practical matter, becomes limited to declaring an act of Congress unconstitutional only when the act violates a specific prohibition in the Constitution (e.g. the Bill of Rights).
Sure, everyone actually has that "power", though of course, certain judicial officers' opinions have more of an effect on society than other people's. Suffice it to say, it's their job to make such determinations, moreso than anyone else.
Did the Court actually make that factual finding itself - that the literacy tests were in fact being used to discriminate against blacks? Or did the Court just accept that fact as accurate because Congress declared that Congress had found that fact to be true? Should the Court just accept the accuracy of Congressional findings? As a practical matter, does it have any choice? How could the Court independently determine the accuracy of Congressional findings?
A few things need to be cleared up. First of all, the supreme court has no power to determine findings of fact, but only whether or not the law was properly applied. Secondly, enforcement is a fundamentally executive and judicial, not legislative, function. When the Constitution gives Congress the power to enforce anything, it's not overriding Articles II and III; it's simply giving Congress the power to empower the proper executive and judicial authorities to do their job in enforcing the law - particularly by specifying what the consequences should be for violating it. It does not give Congress the power to pass new restrictions on activity, or to actually conduct investigations and proceedings themselves.
Now, although SCOTUS can't make any determinations of fact themselves, they can examine the proceedings of lower courts, to determine if the rules of presenting and examining evidence were properly observed. But there has to be a lower court ruling to begin with, which there apparently wasn't, in this case; Congress decided to become judge, jury, and executioner all on their own, which, IMHO, is flagrantly unconstitutional. The proper way of handling it would be the same way government handles any discrimination complaints in the private sector: by having the proper (Congress-appointed) authorities investigate to determine whether or not unlawful discrimination is occuring, and to take appropriate corrective action in those particular cases where it is found to be occurring.