I've been following the immigration debate pretty closely. I watched President Bush's address the other evening, for example. I also read The New York Times and Michelle Malkin's blog, both of which provide good coverage. Philosophically, the most interesting aspect of the debate is the concept of amnesty. Here is the definition provided by the Oxford English Dictionary, 2d ed.:
amnesty, n.
1. Forgetfulness, oblivion; an intentional overlooking.
2. a. An act of oblivion, a general overlooking or pardon of past offences, by the ruling authority.
b. spec. Amnesty International, an international organization, founded in 1961, whose principal purpose is to uphold and campaign for the human rights of prisoners of conscience; freq. abbrev., as Amnesty; formerly the (Appeal for) Amnesty Campaign.
President Bush denies that his immigration policy (which he calls "Comprehensive Immigration Reform") constitutes amnesty. See here. His critics insist just as vociferously that it does. See here. What sort of disagreement are they having? Is it a factual disagreement? (In other words, do the parties have contrary or contradictory beliefs about how things are?) Is it an evaluative disagreement? (In other words, do the parties have different values?) Are they using the term "amnesty" in different ways?
I don't think there's any factual disagreement. By now, the details of President Bush's policy are clear. The parties also agree that amnesty is unacceptable, so there doesn't appear to be an evaluative disagreement. President Bush's critics reason as follows: Amnesty is unacceptable; President Bush's policy confers amnesty on illegal immigrants; therefore, President Bush's policy is unacceptable. President Bush accepts the first premise of this argument but rejects the second.
If I'm right, then there is agreement on both facts and values. What's left? What's left is the concept. The concept of amnesty is vague in the sense that the criteria for its application are imprecise. Critics of President Bush's policy think that anything short of prosecution or deportation for illegal entry into this country constitutes amnesty, and since President Bush isn't calling for either prosecution or deportation, his policy constitutes amnesty. President Bush thinks that amnesty means conferring citizenship on all illegal immigrants (i.e., pardoning them), and since he isn't calling for that, his policy doesn't constitute amnesty.
In terms of the OED definition, President Bush thinks he is neither overlooking nor pardoning those who broke the law. His critics think he is at least overlooking, and perhaps also pardoning, those who broke the law. Is it a bad thing that the term "amnesty" is vague? I don't think so. Most terms are vague to some extent. (Vagueness is a matter of degree.) This allows for discussion, debate, and linguistic refinement. Just look at the vague terms in the United States Constitution, such as "unreasonable," "due process," and "cruel and unusual." Many of them appear to have been put there on purpose. We might call it strategic vagueness.