And just for review, advocacy consists of logical arguments, emotional ones and character of everyone touched by the argument.
People resonate on these three in varying degrees. Your average "Uncle Liberty" FOX news viewer, for example, will rely strongly on emotional and character arguments, only lightly touching the rational. (why is a much longer post, and again, no slight on FOX viewers, I'm just highlighting an easy example we've all seen)
That fetish completely marginalizes a person who is otherwise solid and in their best interests.
An effective advocate can leverage that and convince somebody to support a much worse person for them, on character and emotion alone.
Your technical, smart, rational geek with modest to poor people skills will not consider emotion very strongly at all, and will be marginal on character.
To them, somebody who is a vital part of the process, but who may not be technical, or reason quite as well as they do, will be marginalized on that basis.
Say we've got a smart person, who is fighting for the people, who happens to have a fetish. The fetish has nothing to do with their policy vision, but they will lose on character arguments every time.
Other examples should be obvious now.
So then, we need to step back and understand the purpose of the dialog. We may be thinking, "let's get at the truth", where a bunch of people may be thinking, "let's make it better" (which is a different thing), and some others may be thinking, "let's make it the way it ought to be."
Honestly, few people are interested in the truth in political discussions. They are more interested in seeing it go their way, or favor them, or see "those other people", "taught a lesson" more than anything else.
Advocacy rules here. The strictly rational doesn't. Sorry.
What does that mean?
Lots of things. First, it means debate isn't the norm most of the time, even though we frame things as such.
It also means stories matter. Yes, stories. Personal experiences are extremely potent advocacy.
Lots more here, but let's just say framing things in terms of debate isn't inclusive enough to be broadly effective given the dynamics of how advocacy actually does work.