If you ask a typical member of the Church of Jesus Christ of Latter-day Saints, the answer you'll likely get (often with an irritated eye-roll), is "No, of course Mormons don't practice polygamy!"
And strictly speaking, they would be right...sort of.
It is true that the "mainline" Mormon Church--that is, the Church of Jesus Christ of Latter-day Saints, today does NOT authorize or promote a marriage relationship in which a man has multiple living wives at the same time. That much is true.
But to say that "Mormons don't practice polygamy" isn't entirely true. To clarify, you need to understand some of the things that the mainline Mormon (LDS) Church fails to tell the general public, and sometimes even fails to tell their own membership.
1. Members of the LDS Church (The Church of Jesus Christ of Latter-day Saints) are NOT the only "Mormons" in existence.
There are dozens of breakaway sects that call themselves "Mormons" who do practice polygamy. (They are commonly called "Fundamentalist Mormons.") The largest one is the infamous FLDS Church, or Fundamentalist Church of Jesus Christ of Latter-day Saints, which is led by imprisioned "prophet" Warren Jeffs. They are called "Mormons" because they hold to the fundamental doctrines of early Mormonism (including polygamy), they embrace Joseph Smith as their founding prophet, they use the same scriptures as the mainline LDS Church do (Book of Mormon, Doctrine & Covenants, Pearl of Great Price, and to a limited degree, the Bible).
In fact, the only difference between these breakaway sects of Mormonism, in terms of doctrine, is that they believe that the practice of plural marriage is a necessity here and now, in this life (which is exactly what the mainline LDS Church taught until the beginning of the 20th Century). They also differ in who they believe currently has the priesthood authority. But beneath their peculiar dress and differing practices, they're every bit as "Mormon" as the clean-cut boys you see riding bicycles--if not more so.
Some argue that they're more Mormon than the Mormons, because they more faithfully hold to the original practices of Mormonism, which the mainline church has abandoned. Some of the Fundamentalist groups actually believe the mainline LDS Church is in a state of apostasy because they abandoned polygamy, which was called "The New and Everlasting Covenant" (Doctrine & Covenants 132).
2. Many members of the Church of Jesus Christ of Latter-day Saints currently practice "spiritual polygamy."
Spiritual polygamy? Okay, let me explain. Mormonism teaches that marriage can be eternal. Any marriage that takes place in the Mormon temple is said to be a "celestial" marriage for eternity...that is, a marriage that will continue after death in the Celestial Kingdom.
Now, suppose a man marries a woman in the temple. They are said to be married "for time and eternity"...that is, married both in the here and now, and in the life to come. Now, if his wife dies, and he remarries another woman in the temple, they, too are married for time and eternity. Even though he is only living with one wife on earth, the belief is that he will have both wives when he reaches the Celestial Kingdom.
Now, there's another issue--only men can be eternally married (or "sealed" to use the Mormon terminology) to multiple women. Women cannot be sealed to more than one man. Let's return to the previous example of the man whose wife died, and who remarries. If the woman he is marrying is herself a widow who had been sealed in the temple to her previous husband, then she can only be married "for time" to her second husband--that is, the marriage is only for this life. Upon her death, she would then revert back to her first husband, to whom she had been sealed in the temple.
There's another way that spiritual marriages take place. In the same way that Mormons will baptize by proxy for the dead, they can also perform marriage sealings for the dead. That is, a dead (unmarried) woman can be sealed to a dead (or for that matter, a living) man. Likewise, a living unmarried woman could be sealed to a dead man. The belief, then, is that the man will have all the women who have been sealed to him when he reaches the Celestial Kingdom.
3. The doctrine of the Church of Jesus Christ of Latter-day Saints STILL teaches that polygamous marriage is necessary for exaltation to godhood.
This is a problem. This doctrine is still canonized in their scriptures (see Doctrine & Covenants, section 132). Now, because this is an uncomfortable contradiction between today's practice and the scripture's commandment, the mainline Mormon Church all but ignores this section of scripture in their day-to-day teachings...and if it becomes unavoidable, they often redefine the terms and find other ways of explaining things away. But a straightforward reading of Section 132 makes no mistake--polygamy is for THIS LIFE and is an EVERLASTING COMMANDMENT OF GOD.
They often resolve the conflict between their doctrine of polygamy, and their modern-day failure to practice of polygamy, by saying that polygamy will be practiced in the afterlife, and there is also speculation that at some time in the future, polygamy will be re-instated here on earth for the LDS Church. However, these excuses fail to treat the passage honestly.
What the Mormon Church wants you to believe about polygamy...
1. “The LDS Church has nothing whatever to do with those practicing polygamy."
You'll hear this often, but it is a misleading statement. The Fundamentalist (polygamist) Mormons may not be organizationally connected to the LDS Church, but they are historically and doctrinally connected. LDS Church has EVERYTHING to do with those practicing polygamy, because those who practice polygamy (such as members of the Fundamentalist Church of Jesus Christ of Latter-day Saints) do so because the mainline LDS Church abandoned the practice of polygamy, which at one time had been taught as an absolute necessity for exaltation. Mr. Hinckley had even gone so far as to publicly state that "there are no Mormon Fundamentalists" and that "they are not members of this Church.... If any of our members are found to be practicing plural marriage, they are excommunicated, the most serious penalty the Church can impose. Not only are those so involved in direct violation of the civil law, they are in violation of the law of this Church.” The problem is, polygamy was ALWAYS against the law, even when it was practiced by Mormons in the 1800s. There never was a time when polygamy was not against the law in the United States or in Mexico (to which the Utah territory originally belonged when the Mormons moved westward). It is a very strange thing, then, that Mormonism has publicly denounced the practice, lied about the history, and have secretly held on to the doctrine. But...then again, in the 1800s, when the church was practicing it, the leadership lied to the public about it then, too.
2. "God commanded some of the prophets of old in the Bible to practice polygamy; likewise, he commanded the early Latter-day Saints to practice polygamy."
In an attempt to justify early Mormon polygamy, many Mormons point to the Bible. After all, Abraham and Jacob and David and Solomon had more than one wife. That may be true, but never, and in no way, does the Bible ever say that God commanded them to take additional wives. In fact, if you read the accounts carefully, their practice of polygamy was evidence of their lapses in judgment, and overall dysfunction and faithlessness...NOT their obedience to God's command. God's view of marriage as revealed in the Old and New Testaments always present his intention for marriage to be monogamous. So it is not only an outright lie, but it is an assault on the character of God to suggest that God commanded the practice of polygamy. So using the Bible as a template for the Mormon practice of polygamy is completely bogus. In addition, there are serious problems with the claims that God commanded early Mormons to practice it. For one, Joseph Smith's "revelation" about polygamy comes about shortly after Joseph Smith was caught by his wife in the middle of an lecherous encounter with a young girl. The overwhelming weight of historical evidence--not to mention common sense--points to the so-called polygamy "revelation" as being a guilty man's attempt to cover up his sin and call it a command of God--which makes it doubly reprehensible.
3. Polygamy was practiced on a very limited scale, and for a very short period of time, for the purpose of procreation, or "raising up a righteous seed."
Well, it is true that polygamy in the 1800s was NOT practiced by all Latter-day Saint men. But it WAS practiced by the vast majority of Latter-day Saint women, to say nothing of many young girls. Why? Well, it's simple arithmetic. There were roughly an equal number of men and women in the Utah territory (in fact, there were slightly more men than women). If a man takes two wives, that leaves one man without any wives. If a man takes fifty wives, then 49 other men have to do without. So yes, it's true, polygamy was usually limited to the men who were most favored or who were most wealthy (which were generally one and the same thing). The women (and sadly, young girls) on the other hand, became a "hot commodity" in the early Mormon Church, traded and treated like chattel. The idea, however, that this was all about procreation is bogus for the same mathematical reason. Polygamy does NOT improve a woman's ability to produce more children. It only serves to concentrate the overall number of offspring to a smaller pool of men, whose children sometimes numbered into the hundreds. (It also begs the question: how can those children expect to have any meaningful relationship with a loving father, if they have hundreds of siblings?)
4. "There was a surplus of women in the Utah Territory, and so one of the reasons for polygamy was to help care for those who had no husband."
As we mention above, this of course is a complete falsehood. Census records taken in Utah indicate that there never was a surplus of women; in reality, men slightly outnumbered the women. The story often goes that many of the women were civil war widows, or possibly widows of Mormon missionaries. There is nothing to suggest that either of this was true. But...even if there had been a surplus of women, why would "caring for them" necessarily require them to be married? Would not a charitable church lovingly care for the widows and orphans among them, just like the early Christian church did for the needy among them? The early Christians did not need to force widows and orphans into their beds and enslave them to polygamy in order to rightfully provide for them.
No. Polygamy is a part of Mormonism's heritage for one reason, and one reason alone. Joseph Smith, the founder of Mormonism and the "prophet" who "revealed" the doctrine of plural marriage, could not keep his hands off of women. History bears out that his weakness for adulterous affairs with young women long preceded his "revelation" about polygamy. When all the historical facts are laid out, the only reasonable conclusion that any objective historian can come to is that Joseph Smith's revelation on polygamy--Doctrine and Covenants, section 132--was nothing more than a transparent attempt at falsely justifying his sexual appetite for lechery and adultery, by attaching religious language and "thus saith the Lord" to it. When Joseph Smith died, he had at least 34 wives; several were in their early teens, and a third of them were women who already had living husbands! It was not unusual for Joseph Smith to send a man "on a mission" and then proposition his lovely wife to be his spiritual bride in her husband's absence.
And sadly, this doctrine and practice took root in the hearts of other men who likewise enjoyed the idea of multiple wives and sexual partners, and the result is the enslavement of countless millions of women, children (and even men) who have been decimated in its wake.
So don't believe the Mormon rhetoric about having nothing to do with polygamy. It's a complete lie. The mainline Mormon Church has been trying desperately to gain some credibility and respectability in the broader religious community in this country, and they know that polygamy is a large, embarrassing wart on their face, that they're trying desperately to surgically remove--with rhetoric, revisionist history, obfuscation, and blatant lies. There are other "warts" that they are likewise trying to cut off using the same revisionist tactics, including their racist doctrines and policies, in which people of color were prevented from holding the LDS priesthood until 1978. Like doing away with polygamy, doing away with the racist policy was less about changing doctrine, and more about putting another coat of whitewash on a tomb full of dead men's bones.
*******************************
Addendum: The Mormon Church has recently published several essays on polygamy, mostly in response to accusations that they have systematically lied about and obfuscated their polygamous history. Those essays, even though they do not paint a complete picture, do provide some information that was previously not well-known, including the fact that Joseph Smith was married to as many as 34 wives; that several of those wives were teen-agers, some as young as 14; and that several of his wives were already married to living husbands. These essays can be found on lds.org, at the following links:
Plural Marriage in Kirtland and Nauvoo:
[https://www.lds.org/topics/plural-marriage-in-kirtland-and-nauvoo]
Plural Marriage and Families in Early Utah:
[https://www.lds.org/topics/plural-marriage-and-families-in-early-utah]
The Manifesto and the End of Plural Marriage:
https://www.lds.org/topics/the-manifesto-and-the-end-of-plural-marriage?lang=eng