I see your point, though. They shouldn’t have allowed fear to influence them. But in my youth, I lived in that kind of neighborhood to be closer to work. Most people who write comments here would have done what Palmer and Hartmann did in that situation.
Canvassers in those neighborhoods need to be young, in very good physical condition, very well trained in self-defense and have a large contingent of tough security guards with them (trained fighters with cameras connected to the Net, remote security watching over them, etc.). They really need a small army with them. They’d be surrounded by a foreign nation resembling Winnie Mandela’s mob.
Unless there's some other reason for the withdrawal that we don't know about, those lawyers violated their professional obligations. Sometimes the client wants to do something that the lawyer doesn't think he can do, but that's clearly not what happened here: The campaign actually dropped their more controversial claims after Porter Wright withdrew. The only innocent explanation I can think of is that the campaign no longer wanted to pay Porter Wright's fees--they have certainly gone with what appear to be less expensive lawyers since then.
I know this is not specifically what we were talking about, but as a lawyer I feel the need to rant about it.