Short post, and a good example of a grammatical subtlety, both correct and incorrect. From The Washington Post, no less.
The 2020 election will come down to two important questions: Who actually votes, and who do they vote for?
The second “who” is incorrect. People commonly use “who” when it’s the first word in a context, even when it should be “whom,” as here. That “who” is the object of the preposition “for.” Put the clause into indicative word order instead of interrogative, and you get “they vote for whom.” Easier to see now, isn’t it? A related trick: replace the “who-whom” with “him.” Now it’s even easier to see.
Even the big guys get it wrong occasionally. Maybe they didn’t want to sound like curmudgeons.