So I know there are smarter people out there who've thought about this, but here's my nutshell take:
Let's assume that it's true that deconstruction complicates interpretation in that it opens up numerous possibilities for the interpretation of a given text, including a statute or a prior judicial opnion.
Is this a revelation to anyone? To anyone whose been to law school, that is? The key to good lawyering is, in part, being able to identify as many good arguments as possible in favor of your client. Deconstruction is useful to lawyers to the extent that it opens up new possibilities for argument, but is it news to lawyers that a statute has many meanings?
I admit that law is a particularly interesting place for a deconstructionist to experiment, because it is perhaps the most dierect place where words actually exert an impact on society. Law is words that people must obey, or face punishment. That's interesting, to a theorist, because how often is it that the texts that they study (and perhaps therefore their work) could have an impact, could matter as much as it might matter in legal studies, outside the law?
But for a lawyer? If you take the leaset radical idea of deconstruction and postulate that there is some unknown limit to the potential number of valid interpretations out there, and that many interpretations obscured by the words can be justified by reading the text in a search for heirarchies, or by looking in the "margins" of the text, then what? Well, I guess you are strengthened in your belief and training from your law school days that there is always an interpretation that will favor your client-- and you will keep looking for such an interpretation, but other than that, how are you helped? Does deconstruction suggest new possibilities of legal argument? Maybe on the very extreme margins, but not normally.
The fact is that of the mutliplicity of meanings suggested by deconstruction, only a paltry few are likely to be at all persuasive to judges, in part because however much its proponents may protest, deconstruction works at cross-purposes with the law-- the entire point of the law is to limit, to constrain, to mark territory, to say "not this but that," while the entire point of deconstruction as usually practiced is to expose those limiting constraints as arbitrary heirarchies. Meanings that are 1) likely to be exposed by deconstruction; 2) not likely to be exposed by traditional analysis; and 3) likely to be persuasive to judges are likely to number something close to zero in most cases.
Now, as a judge, you have a much different question in front of you. You have text, and rather than simply making an argument as to what the text means, you have to set a limit, you have to say what it does in fact mean, and you have to do so in a way that helps people decide future case and organize their conduct.
If you're that kind of judge, how are you helped by decontruction's insights? Here, as I've said, you can't really be helped, since the point of deconstruction is to expand and explode limitations on interpretation and the point of law is to limit, to prevent, to say, this far and no further and your job as a judge is to (if you will) create a new text that layers a coherent meaning on top of the old text and (almost by definition) provides more guidance, more specific limits as to what the old text means-- i.e., draws a finer distinction between what is this and what is that.
For many judges, though, deconstruction just makes them skittish and scared-- or as Cass Sunstein puts it, makes them "minimalists." The essence of the Sandra Day O'Connor "oh, this is so complicated, less not decide anything other than the case before us" school of judging maps pretty closely onto what I take to be the central insight of deconstruction-- i.e., that meanings are complicated, and that limitations are arbitrary and hence bound in future cases to produce arbitrary results. The logical corrollary of this kind of thinking is that we shouldn't put out limitations because they will produce in some future case an injustice.
For my money, this is a backwards way of thinking. Of course limits can be arbitrary and may work injustice in some cases. But the point of law is to guide people as to how to arrange their affairs. The effect of saying, "ask me again later" to every case is that no one knows how to behave or what the consequences will be for their behavior. Only if you accept that people are going to act in a particular way regardless of the law and then try to estimate what should justly be done to a particular person who did a particular thing does it make sense to keep saying "ask me again later" to every case. Maybe there are some areas of the law where the ask me again later approach is warranted, but surely most areas of the law ought not be that way.