It’s not just the left. Ad hominems are the domain of anyone with a poorly thought out or indefensible position that relies on faith, not facts.
Try disagreeing with a Birther, for instance. If you don’t sip the kool aid, they’ll immediately call you an Obama plant or a troll. They’ll have a few facts handy, but their appetite for more drops off fast if it contradicts what they want to hear.
It’s no different than ‘Lower taxes for the rich are racist’ argument I’ve heard from a liberal co-worker. There’s no intelligent way to argue this; either you believe it or you don’t. If you try to argue it, then your motives as a human being become suspect, and the Believer has no need to treat you or your words with respect.
It’s faith masquerading as intellectual laziness. That’s why they attack right away on a personal level. They know perfectly well that thinking the issue further through is not helpful to maintaining the logical integrity of their beliefs, and in fact leads to heresy.
“Try disagreeing with a Birther, for instance. If you don’t sip the kool aid, they’ll immediately call you an Obama plant or a troll. They’ll have a few facts handy, but their appetite for more drops off fast if it contradicts what they want to hear.”
Congratulations - you have succeeded in committing an impressive number of fallacies in relatively few words. Let me help you clean this up.
Try for starters
A Practical Study of Argument
by Trudy Govier
http://www.amazon.com/Practical-Study-Argument-Trudy-Govier/dp/0495603406/ref=wl_it_dp_o?ie=UTF8&coliid=I1O92ABB34Q5RM&colid=3R6M7KESRKYFW
Attacking Faulty Reasoning: A Practical Guide to Fallacy-Free Arguments
by T. Edward Damer
http://www.amazon.com/Attacking-Faulty-Reasoning-Practical-Fallacy-Free/dp/0495095060/ref=wl_it_dp_o?ie=UTF8&coliid=I1PD8TIFRX2F3L&colid=3R6M7KESRKYFW
Theories of Truth: A Critical Introduction
by Richard L. Kirkham
http://www.amazon.com/Theories-Truth-Introduction-Richard-Kirkham/dp/0262611082/ref=wl_it_dp_o?ie=UTF8&coliid=I11RK9B14AV0W4&colid=3R6M7KESRKYFW