LAST week, an angry mob attacked an advocate, Nico du Plessis, physically outside court for defending someone accused of kidnapping a child. In the same week, sections of Twitter — at times the cyber equivalent of an angry mob — attacked senior counsel Dali Mpofu for taking Gareth Cliff on as a client.

The thinking behind both attacks was the same: "How can you defend a child abuser?" "How can you represent a racist?"

When I was a public defender — a free lawyer provided to accused people who cannot afford their own — I used to get asked the same question: as a feminist, how can you live with yourself defending domestic abusers? How can you sleep at night, defending sexual offenders?

My answer then was the same answer I give now: because I believe in justice. And, perhaps more importantly, because it is a lawyer’s job (whatever he or she believes) to serve justice. This is why, despite having very little sympathy for Cliff, I will defend to the death Mpofu’s right to represent him.

When it comes to criminal cases, a person is presumed innocent until proven guilty. People repeat this as a platitude, but it cannot be emphasised enough. History is replete with examples of wrongful arrests and false accusations. Even more so in SA, where police work can be shoddy. I have a friend who spent four days in Pollsmoor prison because he happened to be wearing a blue hat. I am not making this up.

But even when the accused is guilty as hell, justice is best served if he has a lawyer. This is because justice is as much about the process as it is about the outcome.

For a judge to come to the right conclusion, she must begin without any set view as to who is right or wrong. She must hear both sides and then decide. The best outcome is most likely to happen when the most competent argument is given from both sides. This way, lawyers help the court to a just outcome.

Over the years, a host of rules (court rules and rules of professional ethics) have been developed, all to serve the same crucial end: so the judge can best hear both sides and come to the most just conclusion.

One of these, which applies to advocates, is called the cab-rank rule. This requires that an advocate must take a case if he is asked. Whether he likes the client, or whether he agrees with the client, are irrelevant.

The rule is there to serve the proper administration of justice. It means that anyone who is forced before a court (a criminal accused) or who wants to go to court (an aggrieved litigant) will have a lawyer and be properly heard. It also protects advocates because it separates them from the cause of their client and consequently from the kind of populist attacks we saw last week.

If you look at the advocates’ professional rules, some of them can appear stuffy and pompous. Okay, some of them are stuffy and pompous (why should seniors sit at the front?). But mostly, they are there to facilitate this same end.

The cab-rank rule is one such rule. There are a host of rules on fees — to ensure access. Another one is the rule of professional courtesy.

Counsel can be strident and combative, but there is a line they should not cross. I’ve seen this line being crossed way too often over the years. Counsel should not get personal and insult each other. They should not interrupt each other. And we, in the public, should not be so gleeful when they do.

I am also guilty of this (it makes such great copy!). But that kind of behaviour does nothing for justice.

At best, it is an entertaining sideshow. At worst, it actually prevents a judge from hearing valid and important arguments.

•   Rabkin is law and constitution writer