Whoa, hold on partner. First, we were talking about polygamy among the Old Testament fathers. The Bible is clear that they did practice, even the beloved King David. Intermarrying with pagans is a different issue altogether. Of course they were told not to do that. I don’t see what bearing that has on King David or his great son King Solomon having over 600 wives and concubines. Please explain.
I never get very specific about the Bible, because I am not a Bible scholar, so I’ll leave that for others. However, it is clear that Solomon deteriorated as he took on the trappings of wealth and wives. It is true that there are a few reported instances of polygamous situations among the early Hebrews, but they are consistently the result of disobedience and always result in less than happy endings. From the beginning, the model for marriage has been ONE MAN, ONE WOMAN. God created Adam and Eve and set them over the creation as the dominant creatures. He didn’t create ONE Adam and several EVES, as one might expect him to have done if he desired polygamy among men. After Abram was given the promise, he and Sarai got impatient and so he took on a foreign wife to make a son who wasn’t the son of God’s will, but the son of man’s will. There is more, but space is very limited. I hope you get the general idea.
Christianity came along and polygamy became a taboo practice. Polygamy was not expressly condemned in New Testament Scripture. It was implied, but Jesus nor the apostles taught extensively about it.
OK, let’s start with the Christians, then. I won’t get into the specific NT arguments against polygamy, though there are many. The fact is, Catholicism and Christianity-at-large have consistently taught polygamy to be sinful. This covers the last 2,000 years and going. Even if the scriptural statements are not “express” as you claim, they are nevertheless CLEARLY implied. Catholics don’t need things to be expressly stated in Scripture. We are perfectly able to flesh out the full meanings of Scripture through reasoning, under the leadership of the Magisterium, which has been given authority by God to do just that.
Instead of telling me that they exist, please show me some evidence. I haven’t seen any and am willing to look at anything you may have to that effect. If you can point out racism in the posts here on the forum please do. Again, please show me. I’m not lazy. I simply haven’t seen them. If they do exist, again, isn’t it possible that it’s a personal mislead ideology instead of a church teaching?
OK, there’s a current thread, which I started a few days ago, titled Do Mormons Believe This? It has some info, and some links to more info. I can also recommend a book or two for you, let me know if you want titles. I’m sure the ex-Mormons here would also be glad to show you quite a bit more than I am able. I am not an expert on Mormonism, but I do know a few things, thanks to this forum and some personal reading.
You certainly are sure of yourself. Yes, Joseph Smith Jr. said the New Jerusalem/Zion was to be in Independence, Missouri and there is a temple that itself now rests in the hands of the RLDS after legal battles with the LDS leadership in SLC. I’m well aware of that. I don’t see how that view makes them nationalists to the extreme.
Maybe it depends on how one defines “nationalism.” One assumes there is more than one way to apply it. Personally, and I am not alone in this opinion I assure you, I believe that Mormonism is a product of the peculiar American view of itself in the world. Rather than make a case for this here, in this thread, off topic, taking up space, I would recommend you do some reading. Again, let us suggest some titles for you.
I’m not convinced that you have studied Mormonism as much as you say

and am surprised by your assertion that my studies are somehow inadequate. Come now, must we travel that road? Simply agree or disagree without judging each others intelligence or abilities?
Sorry if I have insulted you, but you’ve already admitted that you are not aware of the racist or nationalist aspects of Mormonism. Considering that these things are never far from the skin of Mormonism, your lack of knowledge in these areas suggests a lack of study. That is neither good, nor bad, and I make no judgement in that regard. I merely suggest, respectfully, that you do some study, both here on this forum, and some outside reading, and see what you find out.