Whoever vs. Whomever

I came across this sentence in a text I was issued for a seminar: "Give the package to (whoever, whomever) comes to the door." The correct response was listed as "whomever."
The rationale for this was: substitute "he" or "him," as in "give the package to him." Therefore, in this sentence, "whomever" is correct.

I called a local community college that has a grammar hotline, and their response was that "whomever" was correct because it was the object of the proposition "to." I then asked the hotline person what function "comes to the door" served in this sentence, and she responded that it modified whomever!

Please, someone back me up here. "Whoever comes to the door" is a noun clause that is the object of the preposition "to," actually functioning as an indirect object in this sentence. Within the clause, the subject is "whoever." By virtue of the fact that it is the subject, it has to be in the nominative case - whoever, rather than whomever.

Speaking as a teacher, I get irritated when I see questions like this in an examination. I feel that it is a trick question. I hope it was not in an exam for those learning English as a Second language.

It is grammatically correct to say whomever but I doubt is one in a thousand would say it. Most people would say whoever.

There is an old joke passed around by teachers of grammar. Saint Peter in heaven heard a knock on the door. "Whose there?" he asked. "It is I," was the reply. "Heck!" said Saint Peter. "Another one of those damn grammar teachers."

Grammatically, it is correct to say, "It is I." But not one in a thousand says it. Most say, "It's me."

Grammar teachers are passing around a joke that asks "Whose there?"?

Let me go point-blank first.
'Whoever' is correct.

Now here is my analysis.
At first glance, it seems confusing. If you focus on 'to' which is no doubt a preposition, 'whomever' is attractive. But if you take 'comes' into consideration, the nominative 'whoever' is a possibility. Now let's adopt a different angle to get out of this confusion.

First, the [who(m)ever ...] clause is a noun clause. Prepositions take nouns as their objects. (Forget about some exceptions like 'give him up for dead.') So, 'to' belonging to the preposition club is fully satisfied, since it takes a noun as its object. Now let the 'to' matter rest.

Second, with the 'to' matter behind, whether to choose 'whomever' or 'whoever' has now become an internal matter within the [who(m)ever ...] clause. Then the choice is obvious.

This way, 'whoever' satisfies both 'to' and 'comes' while 'whomever' never does.

Please let me add this: Sentences spoken by native speakers do not always reflect the grammar rules.

The correct answer is "Give the package to whoever comes to the door".
The agreement is always within the subordinate clause, not within the main clause, when there seems to be a conflict.

Give it to whomever you like best. (You like him best.)
Give it to whoever pays the highest price. (He pays the highest price.)

Introduce whoever you think is the tallest to whoever you think is the shortest.
Introduce whomever you invited first to whomever you invited last.
Introduce whoever arrived first to whoever arrived last.

It is whoever you think it is.
It is whoever you think has made a mistake.
It is whoever has made the mistake.
It is whoever is knocking at the door.
It is whomever they designated the leader.
It is whomever you believe they sent.

CJ