A tough question. I haven't done extensive review so I couldn't answer the question confidently. But I would think something like this - a 1929 screed by Joseph Goebbels. Refering to the title subject ("The Jew") Goebbel writes things like "He is a negative, and this negative must be erased from the German system, or he will forever corrupt it."
Yikes! That's evil stuff.
In fact I've read about half way through and it's so evil I honestly don't feel like finishing reading it.
I'd guess something like that is the most evil column ever.
Jeffery Tucker, of the Ludwig von Mises Institute, corrects me (thanks, Jeff!). Apparently "the most evil column ever" is a column by Paul Krugman where he gives reason to doubt the reliability of S&P, provides some arguments for how we ought to reduce the debt, and suggests that Congress is behaving less than admirably.
I would have thought inciting violence against Jews in Germany in 1929 beats this one out on evilness, but apparently not.
Keep in mind Jeff Tucker is particularly tuned in to newspaper evilness. It was only last Fall that a great New York Times piece explaining the intellectual backdrop of the Tea Party (unique amidst a lot of coverage suggesting there was no intellectual backdrop) was branded a hit piece by Tucker.
How can a guy that has bourbon for breakfast be wound so tight?