Why does the 13th Amendment (prohibiting slavery) have a section sayin congress can prohibit slavery

It goes to whether the US legislature can make laws enforcing the constitution without a clause in the amendment specifying that they can make laws enforcing the constitution.

If what the constitution says is a law then congress making laws that define penalties is appropriate.

False.

Congress has the power to make laws only regarding subjects that the Constitution says it can do. So you must look to the enumerates powers in Art I or in the amendments that say “Congress May…”

Whether or not you call the Constitution itself a “law” is irrelevant.

Whack-a-Mole, in the mid-1800s, there was considerable doubt as to exactly how much power the federal government could arrogate to itself in the absence of specific grants of that power. For example, Madison vetoed a bill in 1817 that would have allowed federal funds to be used to build a system of roads and canals, relying on the interstate commerce clause, etc. His reasoning was that, in the absence of a specific reference in the Constitution to a power to build such improvements, the federal government was precluded from doing so (it should be noted that, at the convention, Madison had argued for a clause allowing Congress to pass such laws to be added to the Constitution, so this was an ongoing argument). There are a number of other examples from the early-to-mid-1800s of disputes over what the federal government could do in the absence of a specific provision.

Further, the wording of section 2 (appropriate legislation) allows Congress to do things that aren’t directly related to the prohibition in Section 1. So any and all enabling legislation is allowed. The similar section in Amendment XIV has been used to authorize a ton of legislation over the years, including a lot of the civil rights legislation of the 1960s.

It’s worth noting that such clauses were first added to amendments following a bloody war fought in large part over the power of the federal government vs that of the states (specifically on the question whether the federal government had the power to regulate slavery nationally). These clauses left absolutely no doubt that the federal government had such power.

Why would they be?
I - V, VIII bans the (Federal) government from certain acts. The solution would be handled in Court (like throwing out evidence or dismissing charges)
VI and VII are judicial in nature.
IX and X are the unenumerated rights and states rights clauses.
XI is judicial in nature
XII is on the election of President and Vice-President.

So why would Congress ever have to pass a law enforcing those amendments?

Are you telling me there is no jurisprudence about these things in the last ~230 years because no one has passed any laws that impinge on these things?

Please tell us what you think needs to be enforced by Congress (not the courts).

Note that these provisions do not give the federal government the authority to enforce the amendments, they specifically give Congress the authority to pass laws to enforce them.

Maybe you should explain what exactly you think Congress could have or might have done with respect to those amendments.

Aw, darn. That was the easy one, the gimme, the eighteen-inch putt.

I take it back. Maybe it wouldn’t have been so easy.

[Moderating]

I think that we’ve had all the productive discussion we’re going to get, here.