Here is the text of what I put into audio, which is of course easier to search. Basically, he says people are lying when they refer to it as the fugitive slave clause. He cites in response James Madison's Notes - that huge telephone book-sized volume of what is in a lot of ways a CSPAN transcript of the Constitutional Convention. Douglass clearly read Madison's notes.
https://en.wikisource.org/wiki/The_American_Constitution_and_the_Slave
Douglass said: (with some truncation) "But there is one other provision, called the “Fugitive Slave Provision.” It is called so by those who wish it to subserve the interest of slavery... knowing as I do the facts in the case, that I am utterly amazed, utterly amazed at the downright UNTRUTH which that very simple, plain statement really conveys to you about the transaction ... a proposition for the return of fugitive slaves to their masters precisely as criminals are returned. And what happened? Mr. Thompson-Oh! I beg pardon for calling his name - tells you that after a debate it was withdrawn, and the proposition as it stands in the constitution was adopted. He does not tell you what was the nature of the debate. Not one word of it. No; it would not have suited his purpose to have done that."
Douglass: "Very well, what happened? The proposition was met by a storm of opposition in the convention: members rose up in all directions, saying that they had no more business to catch slaves for their masters than they had to catch horses for their owners - that they would not undertake any such thing, and the convention instructed a committee to alter that provision and the word "servitude," so that it might apply NOT to slaves, but to free-men — to persons bound to serve and labour, and not to slaves."
I think it's clear that Douglass means that the clause means not "only" slaves but any kind of labor including - yes - slaves.
I didn't read it all in this moment but I think Douglass is making the point that it's actually the fugitive laborer clause.
"The US Constitution also requires fugitive slaves to be returned to their masters."
Citing Douglass, a simple plain reading of the Constitution itself on its face proves that, well, it does not say that. You're deriving an interpretation and nothing more of ghost words not anywhere found.
No matter what, I think both you and I can agree on this fact: The word slave does not appear there or anywhere. If we really wanted to get deep into the thick of it, we could cite Madison's Notes and explain in detail why it doesn't, since those do exist in writing.
He says they are lying? Is this some form of "Who ya gonna believe, me or your lying eyes?"
Article IV, Section 2 is clearly about fugitive slaves.
"Very well, what happened? The proposition was met by a storm of opposition in the convention: members rose up in all directions, saying that they had no more business to catch slaves for their masters than they had to catch horses for their owners - that they would not undertake any such thing, and the convention instructed a committee to alter that provision and the word "servitude," so that it might apply NOT to slaves, but to free-men — to persons bound to serve and labour, and not to slaves."
So they objected to the word slave? We knew that. You can tell by how it is written that they went to a little effort to avoid mentioning the reality of what they were passing.
I think it's clear that Douglass means that the clause means not "only" slaves but any kind of labor including - yes - slaves.
A teeny tiny sliver of the numbers of people "bound to service." I assume this means "indentured servants", but by far, the dominant meaning was slaves.
I didn't read it all in this moment but I think Douglass is making the point that it's actually the fugitive laborer clause.
With the vast majority of these fugitive "laborers" being slaves.
No matter what, I think both you and I can agree on this fact: The word slave does not appear there or anywhere.
It also doesn't appear in the section where congress can ban the import of slaves in 1808, but that is precisely what they are talking about.
They used euphemisms, probably because they just didn't want the word "slave" put into the constitution. They did the same thing when the wrote the Corwin Amendment. It is totally and completely about slaves, but they didn't use the word "slave."