A Quandary

[brogine]

. . . dashing off memos urging reconsideration of the project to whoever would listen.
Wrestling with Moses
Anthony Flint

Whoever, whomever . . . I thought this the easiest
issue in grammar. But this has me in a tizzy.
Perhaps it’s an issue of proximity, as when the guy
on public radio says, “Investment in securities involve
the risk of loss.”

Your bouquets and brickbats humbly solicited.

[Slava]

For me, it would help to know when this was written. Whom has made a comeback within my lifetime, so if it's oldish, it might have been considered proper at the time.

For current usage, if I'm ending a sentence with a preposition, I use who; Who are you giving it to? Only in formal writing or speech do I use whom; To whom are you giving it?

[brogine]

The book was published in 2009.
You seem to be suggesting that ‘whomever’ would actually be correct. Bouquets, I think, to you.

[Audiendus]

This is a difficult one, but I think 'whomever' would be grammatically wrong in this case (no pun intended).

"Whoever would listen" is a clause, with "whoever" as its subject, so it should be in the subjective form. The preposition "to" introduces that clause as a whole, not just "whoever".

Compare "There is uncertainty about who did it". It would be incorrect to say "...about whom did it".

[Dr. Goodword]

But I'm OK with, "About whom did you write?" In this case the phrase subject is you and who is the object of about.

I spent months learning how to use whom in grammar school and am gravely disappointed by it loss.