Stormfront would be an extreme strawman example (neo-Nazi / white supremacist in this case.) Anyone, be it the NYT or Joe Random Blogger, will find themselves associated with controversial opinions if they publish editorials from Stormfront. It's not enough to say, "Just saying, is all."

IMO it's fine for them to publish an editorial by Vladimir Putin, as long as he's not laying out a case for subverting elections in Ukraine (or here) or murdering unfriendly journalists. They caught some heat for letting him publish anything at all, if I remember correctly. But I think their decision was defensible, in part because he was writing on a matter of broad public interest, and because no reasonable person would assume the NYT supports Putin's more criminal-leaning behavior.