Conservatives constantly accuse liberals, and especially feminists, of "social engineering." The term implies totalitarian coercion to force people's personal decisions to meet some "politically correct" mold. Wikipedia defines "social engineering" more benignly:
Social engineering is a concept in political science that refers to efforts to influence popular attitudes and social behavior on a large scale, whether by governments or private groups.
As the Wikipedia article observes, social engineering, despite the negative connotations of the term, is not necessarily a bad thing: Virtually all law and governance has the effect of changing behavior and can be considered "social engineering" to some extent. Prohibitions on murder, rape, suicide, and littering are all policies aimed at discouraging perceived undesirable behaviors.
Certainly, I don't think that mere influence of popular attitudes and social behavior on a large scale is per se a bad thing at all. I would love, for example, to see more social acceptance of women's career ambitions, more social acceptance of "househusbands," and a more egalitarian division of labor on the home front in more families.
But if we're going to talk about social engineering in terms of its negative connotation of totalitarian interference with people's personal life decisions, I'd have to say that the social conservatives are far more guilty of efforts at "social engineering" than any progressive any day of the week. It is the social conservatives who have entire organizations devoted to the proposition that women should stay at home with their children, that men should play the protector/provider role, that people should only marry the opposite sex, and that our sex should determine the roles we play in society and in life. And they are certainly more than willing to use our legal system and political process to force these personal mores on all of us-- as evidenced by the proposed constitutional amendment to ban same-sex marriage, efforts to ban abortion, and the war on contraception, to give just a few examples. It is the social conservatives who constantly talk about the wide scale societal effects of my personal choices whether to have sex and with whom, whether to have children, and how to care for my children.
Personally, I have a strong libertarian bent.* I would love to see more women litigators because it is better for me not to be a minority as a woman litigator. But that doesn't mean that I would presume to demand that more women go into litigation for the sake of the collective. The social conservative, however, does presume to demand that I marry a man and bear children for the sake of the collective.
It seems therefore that when a conservative talks about "social engineering," what he really means is encouraging attitudes and practices of which he disapproves. If one is encouraging, or even forcing, attitudes and practices which he likes, then I guess it's not social engineering.
UPDATE: I probably should quit using the term "libertarian" to describe myself. I don't believe that free market forces are the means to solving most social problems, and I think that's what the term implies. I really meant to say that I don't like the government telling me what I can and can't do unless my actions have a direct impact on others. Thus, in my world, drug laws bad, anti-discrimination laws good, to give just one example.