It’s a legitimate critic that has been debated at length in the academia. Also you say I used it as a label. I admit I did. But when he defines the moral entrepreneur, Howard S. Becker happens to do that: label groups of people as moral entrepreneurs.
There is no unified classification or characterisation of moral entrepreneurs. Marxists, new left, left libertarians and liberals would all have different views on that. No unified version within each school neither. I would suggest that it is because, at a personal level, we all have a distinct experience and appreciation of what living in a society implies and, where there is presumed victimisation involved, of what agency is. Whatever the groups we adhere to, we want to keep our final judgement to ourselves, our own morality being our ultimate master.
Becker’s three-page definition of the moral entrepreneur is a piece of art in sociological writing.
In it, he’s interested in how rules are created. He explains a process involving rule creators (acting on moral grounds), experts (having their own interests) and rule enforcers (police acting with a larger spectrum of morals concerns). The rule creator (or moral entrepreneur), he says, “operates with an absolute ethic. What he sees is truly and totally evil with no qualification. Any mean is justified to do with it. The crusader is fervent and righteous, often self-righteous.”
I see it as an ideal type, each case having very distinct characteristics. I have a simplified set of emotional criteria to identify moral entrepreneurs. It’s when I feel the devotion, the hatred for some groups of deviants, the willingness to generate fear, and the evil (a very common word in the prohibitionist discourse).
Murphy, Perrin, Smith and Mourani are crusaders on the issue of prostitution. It’s obvious that they are on a mission. When knowledge and testimonies overwhelm their believes, they just turn to other believes or worst, keep telling them anyway. And they have a ton. They are masterminds at creating new language, confusing everybody’s mind. To me, it’s just like going to mass when I was 6. The priest used incomprehensible words — but he was not talking to me anyway.
I know a bit better about Mourani because she’s a Montréal MP. Our little girls are subdued on the streets by gangs of thugs who seduce them, drug them, abuse them and sell them. That’s what a prostitute is, proven by testimonies. That’s it for her, no discussion possible and, as she likes to point out, she’s a criminologist! When she says prostitution is little girls being sold, she’s not using an ethical metaphor about objectification, she’s in the description of the acts of violence and of the dangers facing our children in this evil world. It’s all about generating fear. That’s how churches, the supreme moral entrepreneurs, have always operated.
Moral entrepreneurs rarely succeed in changing the public opinion. But that’s only their ultimate goal. Their more immediate one is to have the law changed. And anti-choice groups in prostitution are incredibly successful at it. The recipe is fairly simple: they blackmail politicians. The first one to speak publicly against criminalisation will be fired on as anti women and will have his past scrutinized to find out shaming material.
On your other examples, abolitionists (slavery) were moral entrepreneurs in a sense, in direct line with the development of the liberal ideas of the Enlightment. I don't think churches had a big role. Cars, gas, arms could be seen also as moral issues, but they are more fundamentally scientific issues at least in a consequentialist perspective.