One difference, I might add, is that though you can find, if you look hard enough, some 19th century Southern Baptists & a few other pastor-types who adhered to this view...these were usually local & regional views.
Plus they were mere "opinions."
That can't be said of Brigham Young's comments...nor of the Lds "prophets" and "apostles" which followed him...You see, the Mormon "prophets"...
(1)...supposedly give "revelations" directly from the Mormon god...those aren't mere opinions...if these were FALSE opinions, ensuing Mormon leaders would have told us that these men were speaking as false prophets (they haven't)
(2) plus it wasn't "localized" Mormonism...but represents (and STILL does...given that they have a university named after him) universal Mormonism! The Mormon "prophets" speak for the entire church. None of their previous leaders' words have been rescinded, rebuked, etc.
That can't be said of Protestants who HAVE and DO repudiate such regional 19th century opinions.
Let's look @ the lineup of Lds leadership views re: Cain:
Brigham Young:
*“Cain slew his brother....and the Lord put a mark upon him, which is the FLAT NOSE AND BLACK SKIN...” (Journal of Discourses, Vol. 7, pages 290-291)
*“The rank, rabid ABOLITIONISTS, whom I call BLACK-HEARTED Republicans, have set the whole national fabric on fire.” (Journal of Discourses, Vol. 10, page 110)
* Per Young, Joseph Smith classified these people as The Seed of Cain. Young said that "Joseph Smith had declared that the Negroes were not neutral in heaven, for all the spirits took sides, but 'the posterity of Cain are black because he (Cain) committed murder. He killed Abel and God set a mark upon his posterity'" (The Way to Perfection, Joseph Fielding Smith, p.105).
Third Lds 'prophet' John Taylor:
Reacting to abolitionist Horace Greeley's visit of Utah:
* “... I WOULD NOT TALK TO HIM: I FELT MYSELF SUPERIOR TO SUCH A MEAN CONTEMPTIBLE CUR. I knew he was not after truth, but falsehood. “This Greeley is one of their popular characters in the East, and one that supports the stealing of NIGGERS and the underground railroad....he is one of the prominent newspaper editors in the Eastern country, and he is a POOR, MISERABLE CURSE.” (Journal of Discourses, Vol. 5, page 119)
* From Black Skin and the Seed of Cain (Mormonism Research Ministry): On two separate occasions, third LDS President John Taylor stated that it was God's plan to allow the seed of Cain to remain on the earth in order for the devil to be properly represented. On August 28, 1881, he declared, "And after the flood we are told that the curse that had been pronounced upon Cain was continued through Ham's wife, as he had married a wife of that seed. And why did it pass through the flood? Because it was necessary that the devil should have a representation upon the earth as well as God" (Journal of Discourses 22:304). The following year, Taylor reiterated his former comment when he said, "Why is it, in fact, that we should have a devil? Why did the Lord not kill him long ago? Because he could not do without him. He needed the devil and a great many of those who do his bidding to keep men straight, that we may learn to place our dependence on God, and trust in Him, and to observe his laws and keep his commandments. When he destroyed the inhabitants of the antediluvian world, he suffered a descendant of Cain to come through the flood in order that he might be properly represented upon the earth" (Journal of Discourses 23:336).
Lds 'prophet' Joseph Fielding Smith...an Lds 'apostle' for 60 years plus became the 'prophet' from 1970-1972:
* “Not only was Cain called upon to suffer, but because of his wickedness HE BECAME THE FATHER OF AN INFERIOR RACE.” (The Way to Perfection, page 101)
“There is a reason why one man is BORN BLACK and with OTHER DISADVANTAGES, while another is BORN WHITE with great advantages. The reason is that we once had an estate before we came here, and were obedient; more or less, to the laws that were given us there.” (Doctrines of Salvation, Vol. 1, page 61)
LDS 'apostle' Bruce McConkie:
McConkie was writing about those who "were more valiant than others…Those who were less valiant in pre-existence and who thereby had certain spiritual restrictions imposed upon them during mortality are known to us as the negroes. Such spirits are sent to earth through the lineage of Cain, the mark put upon him for his rebellion against God and his murder of Abel being a black skin...The present status of the negro rests purely and simply on the foundation of pre-existence" (Mormon Doctrine, p.527, 1966 ed.).
The fact that contemporary Mormons can't bring themselves to condemn these statements or these men tells us a LOT!
That tells me either they, too, are racists...or, that they harbor racism in their midst. Given that Utah Mormons have long fostered animosity vs. monogamy by harboring bigamy and polygamy...this problem shows how out of touch Mormons are socially and Biblically.
Unlike Mormons who weasel around the above statements, let me be unequivocably clear: The above comments stink to the highest heaven...and the stink is still found on the very clothes the Mormons wear today because they won't shed these clothes "odored" by Brigham Young, John Taylor, Joseph Fielding Smith, Bruce McConkie & many other Lds leaders!
I understand the point, but I don’t see enough significant difference between the “opinions” you cite from the Mormon leaders, and the myriad of “opinions” that one could find from 19th and 20th century Souther Baptists. The idea that dark skin was the mark of Cain was cerrtainly not invented by Mormons, and they were hardly the only ones evoking it well into very recent history.
But we can celebrate the blessing that the idea has been discarded by most reasonable folk of either religious persuasion.