X argues for A.
A is vile.
Therefore X is vile.


X argues for A.
X is vile.
Therefore A is vile.

One may use a term in any way minimally consistent with its history, and
for that reason _either_ of the arguments above may be labelled _ad
hominem_. I myself, however, would use the label only for Example 2. The
first one contains a personal attack, but it also, and primarily,
depends on establishing a point about the argument involved. Hence it
can be answered by A without him/her having first to give a self

The second one, however, attempts to discredit the argument without in
fact confronting it, by discrediting the person who makes the argument.
That is my personal usage of _ad hominen_. Most red-baiting (or any kind
of baiting) is an instance of (2).

When Frank Knox (a Republican but in Roosevelt's cabinet) ordered his
paper, the old Chicago Daily News, to oppose whatever the Tribune
supported, Colonel McCormick ordered his editors to launch a campaign
against syphilis. (This is obliquely relevant to the question of ad
hominem arguments, though it does not directly involve one.)

Note that a common argument in u.s. politics is related to the ad
hominem argument, though it does not involve persons. "X is bad because
it is unconsitutional." This says nothing about the merits of X but
merely tries to rule it out of consideration. That is also what an ad
hominem argument tries to do.

Band wagons also involve a suppressed ad hominem argument. The
implication of a "band wagon" is that anyone who does not accept a
certain premise is too (stupid/evil/unfashionable) to be worth arguing
against. Stephen J. Gould, in _The Structure of Evolutionary Theory_,
gives a good account of "band wagon" effects in science in certain