Quorum. You keep using that word. I do not think it means what you think it means.
First, let’s take a step back, but not all the way back. Mostly because this isn’t a book. Let’s go to 1964. At this time, each stake and mission generally included a High Priests quorum, at least one Elders quorum and at least one Seventies quorum. In the years leading up to this time, church policy was that if there were not at least 49 elders (a majority of the scriptural 96–D&C 107:89) then a “unit” en lieu of a quorum was to be organized. But why would that matter? I imagine that the majority of Elders quorums in the church today don’t have 49 members. The answer goes back to the definition of what a quorum is, namely, “the number (such as a majority) of officers or members of a body that when duly assembled is legally competent to transact business” (to quote Miriam-Webster).
Some folks that have served in civic or business organizations that follow old timey rules may be familiar with the idea that you need to have a quorum to transact business. Generally speaking a quorum doesn’t exist unless you have the group assembled. You see this in old minutes of the church as well. Things have changed a lot since D&C 107 was delivered and sustained and many words that are currently fundamental to Mormon self-conception have evolved within the tradition in particular ways (e.g., priesthood and ordinance).
Back to 1964. The First Presidency and the Quorum of the Twelve had some questions about governing jurisdiction within the church, and President McKay asked David Yarn–a Prof at BYU, and smart guy who did stuff like this–to write a position paper that ultimately got published in the Improvement Era. The whole thing is remarkable, but here is a fascinating bit:
When a presiding quorum is to be organized, be it the presidency of the Church, the presidency of a stake, a bishopric, the presidency of a quorum, or the head of an auxiliary, it is the president (or bishop, or superintendent) who is chosen and appointed by the authorizing body…The keys of authority of the particular jurisdiction center in the president. [emphasis added]
There are a couple of things to note about this statement, in light of quorum organization in 1964 generally: First, this construction is less odd when you consider that Bruce McConkie had spoken about Relief Society Presidents receiving keys. Next, in 1964 if Elders quorum members were spread across multiple wards, which was common, they could organize themselves into ward Elders “groups.” However the “group leaders, their assistants, and secretary” were not generally “set apart.” These groups met regularly, but also joined for quorum business at least occasionally. Lastly, at this time, the Stake President was a member of the High Priests quorum, not its president, and these quorums did have regular, albeit not weekly, meetings.
In 1968, however, everything changed. The Priesthood Correlation Committee revised pretty much everything. Perhaps the biggest change was that all of the High Priests quorums in the church were sort of dissolved. Now, technically they were not dissolved, they were simply reconstituted, with the Stake Presidency as the new quorum presidency, and each ward getting a High Priests group, with a group leader, etc. The HP quorums never really met again to conduct business, if you will. All business was managed in the groups exclusively. One of many driving forces within this reorganization was a shifting conception of what “keys” are (another complicated word). Keys grew to be something that only priesthood quorum presidents held in the church. And if the Stake President didn’t have keys, then the system is broken. Things were in flux though–the Q12 was still using Yarn’s rational above at least for a few more years after this change.
Things have stayed fairly static on the priesthood organization side of things, seventies quorums excluded, for the last fifty years. Also, for at least a couple of years after 1968, if a ward did not have at least 49 Elders then multiple wards would combine to constitute a quorum. Eventually no one cared about having a technical majority anymore, because what business was the Elders quorum doing anyway, and every ward got a quorum.
On March 31, 2018 (aka, yesterday) freshly minted Church President Russell Nelson announced another change to things. The High Priests groups in each ward were to be dissolved, with all of their members joining the Elders quorum of the ward in which they reside [n1]. I think that there are several compelling logics for a such a change beyond those stated with the announcement: 1) logistically (especially in developing wards and stakes) multiple priesthood groups attenuated resources; 2) the EQ president and the HP group leader were functionally equivalent, and thus subverted the idea that “only priesthood quorum presidents can have keys” axiom; and 3) Relief Societies have long succeeded with blended demographics. There are some fun resonations with early Mormonism in this structure as well [n2] (note that where HPs fit in early Mormonism is remarkably complicated). Now the High Priest quorum is still to exist, but it is to be comprised of church officers called to governing positions in the church (Stake Presidency, High Council, Bishoprics, and Patriarch). My sense is that the reason that the HP quorum was kept at all, even if it is a logistical fiction, was precisely because the axiom that only priesthood quorum presidents can have keys has become so dominant, and we want the Stake President to have keys.
n1. As a side note, in 1979 the First Presidency and Quorum of the Twelve had a lengthy debate about combining High Priests, Seventies, and Elders into a single ward group for regular meetings. The idea proved too divisive to implement at the time.
n2. Important to this conversation is the reality that there was no High Priest Quorum in the early church. In fact, in the earliest church there were no quorums, but JS swiftly revealed them as the organizational structure for the church. When D&C 107 was revealed in 1835 which organized all of the various quorums, there was only a High Council and a Presidency of the High Priesthood. Basically, those were the governing bodies. Because High Priests quorums were created after this revelation was printed, unlike other quorums, there were no canonical numerical requirements for their existence and also more flexibility to how they were constituted.