A guest op-ed in the Washington Post (by Vanderbilt Political Science Professor John G. Geer) makes the obvious point that "negative" ads are not ipso facto bad (a similar point was made more effectively I think by Jamison Foser at Media Matters, discussed by me here).  They are more likely, the author correctly argues, to provide information to the voter than "positive" ads.  This need not necessarily be the case, but it seems in fact to be the case (the author has empirical research to support this claim). 

My problem with this op-ed, however, is another.  In all of the discussion of "negative" ads, the author fails to distinguish between "attack" ads and "critical" ads.  One might make finer-grained distinctions, as I am sure someone has, but these will suffice for the moment.  Let's say a "critical" ad makes an argument against an opponent's position on some or other issue.  An "attack" ad consists argument free character style attacks.  Those, as anyone can see I think, are clearly different.

A defense of the one kind of negative ad, need not be a defense of the other.  I would argue in fact that defending critical ads entails rejecting "attack" ads as "politically informative."  So this, for instance, strikes me as a false equivalence:

And Obama's not innocent, either. While McCain's running mate, Gov. Sarah Palin, blasted the Democratic nominee for his rather thin ties to a seemingly unrepentant member of the Vietnam-era Weather Underground, Obama responded with an ad reminding voters of McCain's role in the "Keating Five" savings-and-loan scandal of the 1980s. Recent data from Nielsen suggest that the campaigns have aired roughly the same number of negative ads. Even Karl Rove, who knows a thing or two about attack ads, has declared that both sides have gone too negative.

The thin links between Obama and Ayers made by the McCain campaign and Fox News are dishonest and misleading.  Obama's linking McCain to the Keathing Five is another matter.  McCain was a member of the Keating Five (otherwise it would have been four), he intervened on Keating's behalf, had a tight relationship to Keating and helped, in a legislative way, Keating commit fraud.  He was in fact officially reprimanded by the Senate for that.  The Ayers and Keating allegations are not, in other words, in the same logical category.  It would be very helpful, I think, to keep them distinct.