Is it ever possible to use a comma after an essential clause?

Question

Forgive me if my use of terminology isn't quite right...

I'm editing this sentence:

This is a serious problem that ranges from elementary school teachers to adjunct professors such as here, and deserves far more attention than it receives.

The segment "that ranges from teachers to professors such as here" plays the role of what I believe is an essential clause. From what I've read, you generally use no comma after an essential clause, as in this example:

The man [who ordered the pizza] tried to pay with a foreign currency.

versus with a nonessential clause:

Mr Brown, [who ordered the pizza], tried to pay with a foreign currency.

Which ARE placed between commas. So, my question is: CAN you use a comma after an essential clause, as in the my above sentence? Or am I required to remove the comma?

The reason I fell into this rabbit hole at all was I at first thought the second clause was a fragment and added a subject, but then I realized it didn't SOUND bad the way it had been... and got super curious!

Let me know if I'm mistaken at all, and thanks in advance.

SECOND UPDATE

Actually, now that I think of it, I'm certain this question no longer has to do with restrictive vs non-restrictive clauses, and rather has to do with the grammar of this sentence:

This is a serious problem, and deserves far more attention than it receives.

Assuming this sentence is grammatically correct, I'm now more confident that the answer I've marked is the correct explanation.

Answer 1

Your instincts are good about when and when not to use commas, and your sentence is punctuated correctly. The comma here does not terminate the non-essential clause "that ranges from elementary school teachers to adjunct professors such as here," but rather marks where the main, independent clause ends and where the second clause begins.

This second clause--"and deserves far more attention..."--shares its subject with the first, and is called an imperative clause. For more information on imperative clauses and their missing subjects (known as "ellipses"), see here.

Answer 2

I'd use another punctuation:

This is a serious problem, which ranges from elementary school teachers to adjunct professors such as those here, and deserves far more attention than it receives.

The bolded is the parenthetical part, the non-restrictive clause. Commas around it.

The rest is the main.

I've changed

that -> which

as this is what Bryan Garner, Modern American Usage, recommends for non-restrictive clauses.

Also

"such as those here"

seems better to me, "such as here" being a bit too unfocussed and casual.

Answer 3

The terminology you are trying to use is called "restrictive" and "nonrestrictive" relative clauses or "parenthetic expressions."

Non-restrictive relative clauses are separated by two commas:

The Baker's son, who is an accomplished piano player, fell and broke his legs on the ski slopes yesterday.

The main thrust of the above sentence is the Baker's son broke his legs. Meanwhile for reasons unknown to us the speaker gave uncritical information about young Mr. Baker's talents: who happens to be an accomplished piano player. That clause, "who is an accomplished piano player" is separated by two commas in each end or placed into a pair of parentheses, for the info the non-restrictive clause bears is not critical to the main statement, it is just additional information: therein the name "parenthetic expression" — parentheses and commas perform the same function.

On the other hand Restrictive clauses are not separated by commas or parentheses, for they are essential part of the sentence. For example,

"This is the house that I wanted to buy, but I could not get financing."

I must add while discussing restrictive and non-restrictive relative clauses, it is critical to make a serious study of relative pronouns that will help to grasp the subject more readily.

And information about them can be accessed either through a good grammar book or even the Internet.

A very modern up-to-date English grammar book is titled, A Student's Introduction to English Grammar, which is the less demanding summary of The Cambridge Grammar of the English Language by Huddleston and Pullum, and it is a lot cheaper than the $300 price for the CGEL.