[Vision2020] the ad hominem fallacy

[No Weatherman]

The Internet Encyclopedia of Philosophy definition of the ad hominem
fallacy (thanks for the link, Dr. Campbell!):

Ad Hominem
You commit this fallacy if you make an irrelevant attack on the arguer
and suggest that this attack undermines the argument itself. It is a
form of the Genetic Fallacy.

Example:

What she says about Johannes Kepler's astronomy of the 1600's must be
just so much garbage. Do you realize she's only fourteen years old?

This attack may undermine the arguer's credibility as a scientific
authority, but it does not undermine her reasoning. That reasoning
should stand or fall on the scientific evidence, not on the arguer's
age or anything else about her personally.

If the fallacious reasoner points out irrelevant circumstances that
the reasoner is in, the fallacy is a circumstantial ad hominem. Tu
Quoque and Two Wrongs Make a Right are other types of the ad hominem
fallacy.

The major difficulty with labeling a piece of reasoning as an ad
hominem fallacy is deciding whether the personal attack is relevant.
For example, attacks on a person for their actually immoral sexual
conduct are irrelevant to the quality of their mathematical reasoning,
but they are relevant to arguments promoting the person for a
leadership position in the church. Unfortunately, many attacks are not
so easy to classify, such as an attack pointing out that the candidate
for church leadership, while in the tenth grade, intentionally tripped
a fellow student and broke his collar bone.

http://www.iep.utm.edu/f/fallacy.htm#Ad%20Hominem

I'm posting this information to demonstrate that the absence of my
identity is not relevant to the substance of my points. I would like
to see supporters of Barrack Hussein Obama address substantially his
long-standing personal and professional connection to domestic
terrorist Bill Ayers and how that connection influences his public
(and private) policy. Instead, all I hear are abusive ad hominem
arguments. But if Obama wins the election and we discover that he's
infinitely more radical than he disclosed during his campaign, will my
identity matter — or will it matter that a lot of people did not ask
the right questions at the appropriate time?

Just a little more fudge for thought.