Here's a further quote from the Dred Scott decision. In particular, I'd like you to note the word that I have highlighted in bold red, and note how that, all by itself, denies even "personhood" to black slaves:
"The question before us is, whether the class of persons described in the plea in abatement compose a portion of this people, and are constituent members of this sovereignty? We think they are not, and that they are not included, and were not intended to be included, under the word "citizens" in the Constitution, and can therefore claim none of the rights and privileges which that instrument provides for and secures to citizens of the United States. On the contrary, they were at that time considered as a subordinate and inferior class of beings, who had been subjugated by the dominant race, and, whether emancipated or not, yet remained subject to their authority, and had no rights or privileges but such as those who held the power and the government might choose to grant them."
That is language in action. And that's what people calling blastocysts "babies" are doing.