Bill Mahr, a comic in the US, has taken on the New York Times for its headline use of “enormity” to mean large as in “The Enormity of the Voter Turn Out in France.” He insists that enormity should only refer to great evil.  That’s a new one on my, but 59% of the AHD usage panel agrees!  Enormousness should be used instead they say.  I confess that I’ve never heard of enormousness and it sounds clumsy. 

Sounds like there’s been a meaning shift toward evil (the French original doesn’t seem to take that meaning), but that’s not clear from AHD.  OED?

Edit: AHD concludes in the usage note:

Writers who ignore the distinction, as in the enormity of the President’s election victory or the enormity of her inheritance, may find that their words have cast unintended aspersions or evoked unexpected laughter.

The brick and mortar OED lists a morality-neutral defintion from 1538 but it’s just “difference from a normal standard...” The evil tinged definition that we normally use today is from 1563.  The plain “hugeness” definition is given from 1792 but marked as obsolete.  They go on to say that one might find recent examples but that it is considered incorrect. 

The E section of the B&M OED was compiled in the period 1888-93.

The AHD usage panel is a useless collection of blowhards (well, I exaggerate, obviously—they’re not all blowhards, but a compiling of usage opinions from a large number of people, however sensible individually, will inevitably tend towards blowhardery).  The MWDEU, the only trustworthy usage reference, has two pages on this, beginning:

The usage experts insist that enormity is improperly used to denote large size and is properly used only to denote wickedness, outrage, or crime.  Enormousness is the word recommended for large size… The recommendation is not just simple, it is an oversimplification…

And ending, after a large number of citations with various shades of meaning:

We suggest that you follow the writers rather than the critics: writers use enormity with a richness and subtlety that the critics have failed to take account of.  The stigmatized sense is entirely standard and has been for more than a century and a half.

Even Safire caved in over a quarter of a century ago:

I think the time has come to abandon the ramparts on “enormity’s” connotation of wickedness. —William Safire, N.Y. Times, 8 Mar. 1981

The earliest citation for enormousness is 1802 :

2. The quality of being excessive in size; vastness, hugeness.
1802 C. WILMOT Let. 15 Nov. in Irish Peer (1920) 114 The Gothic Cathedral [at Milan]..is not yet finish’d from the enormousness of the expense. 1885 W. C. RUSSELL Strange Voy. II. vii. 110 The enormousness of the ocean.

which would suggest that, up until the nineteenth century, “enormity” was used in this sense.

Enormity in its present usage is fine. But bring ginormity within a hundred paces of me and you take your life in your hands!

bring ginormity within a hundred paces of me and you take your life in your hands!

Why? Do you prefer gianormousness or humongosity?

I imagine that Maher had been reading his Elements of Style, the ubiquitous guidebook for anal-retentive writing by William Strunk, Jr and E. B. White. Elements of Style has an entry that deprecates this usage.

Very likely indeed.  Much as I deplore book-burning, I would be able to muster up only the feeblest pro-forma objections if all copies of Elements of Style were rounded up and destroyed and all knowledge of it were effaced from the memory of mankind.