Ezra writes that it's "very unfair" to apply the word "eugenics" to, say, the contemporary trend toward the elimination of Down's Syndrome by selective abortion, because "traditionally, the term has been used to denote efforts to direct or encourage breeding by high status, socially dominant individuals in order to select for their characteristics, and discourage breeding by low status individuals (criminals, the insane, blacks, etc) in order to wipe their characteristics from the gene pool. For Ross to conflate that with parents who decide to abort infants with medically disastrous genetic mutations is a real stretch."
First of all, Down's Syndrome is not a "medically disastrous" genetic mutation, unless you take an extremely broad definition of the term "disastrous." Second, while the means of "traditional eugenics" were obviously very different from what's emerging now - involving state power rather than parental choice, and selective breeding/sterilization rather than prenatal genetic screening and abortion - the ends were the same: the genetic improvement of the human species through the scientific management of the reproductive process. Obviously, the question of whether and when to apply the term is contested, since nobody wants to be associated with the way early-twentieth century eugenics was practiced in the United States. But the use of the word to describe the abortion of the genetically-disordered, and the possible long-term Gattacization of reproduction, is hardly a reductio ad Hitlerum; it's more of a reductio ad these guys. Moreover, the usage hardly unique to the political Right - see here and here and here and here and so on. (That guy Habermas: What a wingnut!) Indeed, many defenders of genetic enhancement through prenatal intervention - and by other means as they become available - have embraced the term "liberal eugenics" (to be contrasted with the old, authoritarian eugenics), rather than repudiating it. Which suggests that it's not all that "unfair" a word for conservatives to use to describes the practices and trends in question.