"...will divide the people (who/whom) most need to be brought together" [duplicate]

With a two-party system, our nation will divide the people (who/whom) most need to be brought together.

Do I use who or whom for this sentence? I think that "people" is the direct object and warrants the use of "whom", but I want to make sure I'm right.

Because the subject of who most need is simply who, you have to use

With a two-party system, our nation will divide the people who most need to be brought together.

If you want a whom example, try

With a two-party system, our nation will divide the people whom you most need brought together.

The relative pronoun takes the case of the role it plays in its clause.

A simple rule of thumb is that if you can get away with omitting the relative pronoun, then it must be whom if you don’t omit, while if you cannot omit it and have the sentence still make any sense, then it must be either who or whose.

I like the he/him rule: if you rewrite the clause using he and him and see what makes sense, that tells you whether it's who or whom. Which works better: "he needs to be brought together", or "him needs to be brought together"? I think the former works (ignoring the difficulty of bringing together one person), therefore I think the original sentence needs "who".

Subject | Direct Object | Indirect object | Possessive
======================================================
he      | him           | to him          | his
they    | them          | to them         | theirs
who     | who           | to whom         | whose

As @tchrist pointed out, "the people who need" are the subject of the sentence, so it's who, not whom.

Whom is usually the indirect object of the sentence, as in

"To whom should I make this cheque payable".

When you have a direct object, it's usually who, as in

"He doesn't care who he hurts with his snarky comments".

According to this Oxford Dictionaries blogpost, whether to use who or whom for the direct object is in flux and a matter of personal preference.