There are several reasons for this lasting fascination. First, Schmitt was both very smart and an extremely engaging writer. He could put the deepest questions surrounding democracy, the rule of law, or constitutionalism in a way that can not only be understood by the non-specialist, but that is actually as captivating as a novel. He had a particular flair for the jarring proclamation and famously started off a couple of his books with absolute corkers.
Second, he is attractive to xenophobes (including unabashed racists and anti-Semites), as well as to extremely partisan "Us vs. Them" types of many other stripes. Whether or not his signing on to Nazism and descent into explicit anti-Semitism were entirely sincere or more matters of self-protection, his division of the world into "Friends" and "Enemies" certainly makes fandom captivating for those with certain proclivities.
Third, as suggested in the first reason above, his critiques of liberalism, democracy and legal positivism are incisive and deep. Anyone wanting to hang on to some more conventional (read: "acceptable") theory of government or jurisprudence is likely to feel like they are struggling as helplessly as the Nemean Lion in Hercules' grasp. Schmitt's arguments for "decisionism" and against the effectiveness of government by norms of the Kelsenian variety are very, very good.
Schmitt argued that constitutionalism, indeed the rule of law generally, is a kind of pathetic joke. Because, after all, somebody had to make these constitutions and must continue to bless the alleged meanings of their contained provisions if they are to have any effect. Furthermore, since liberalism is animated by a certain sort of proposition, for example, that all people have the unalienable right to free speech, whatever some majority may want, it seems to be contrary to democracy. For the latter requires that the people must get what they want, and that it cannot be subservient even to glorious-sounding propositions. However, democracy has its own needs. It requires that each person be equal to every other one, at least in some extremely important respect, and that is itself a principle of liberalism--or at least an example of what is claimed to be an undeniable truth. Self-government needs equality to make sense, but it cannot itself establish it.
Such considerations may all seem pretty abstract, so consider a particular event: the creation of the U.S. Constitution, a document taken by many Americans to be a sort of divine gospel, handed down to a bunch of conventioneers gathering in Philadelphia in the late 18th Century (arguably for a little bloodless coup). It's worth noting that Schmitt would say that gang pretty much had to have been commissioned by the Almighty for this work, because there wasn't the slightest thing democratic about their pleas for a more powerful Congress. The Articles of Confederation (under which they presumably operated) explicitly prohibited amendment except by unanimous consent of all the states. But, after the failure of a few half-hearted attempts to revise the Articles by Charles Pinckney, the Constitutional Convention convened and simply blew the whole thing up and started over. By what right could that batch of "founders"--or anyone else not specifically sanctioned by the Articles --have produced a law with actual effect? (And, of course, the same objections may be brought against the drafters of those old Articles.)
A similar description would fit the birth of the Weimar Constitution ("formally promulgated" in 1919) with which Schmitt was so closely connected: as no people gave anyone the authority to claim that document was law (and how could they?) either such authority was granted by the heavens or was simply taken as if it had been. And in either case the drafters would have to insist on the existence of one or the other brand of authority. For Schmitt, that means that some person or group would have to make a decision. Even if that decision provides for an extremely democratic parliament, it can have done so only in an entirely undemocratic fashion. It must have simply taken control and winged it.
In spite of appearances, this situation isn't essentially changed once a constitution is claimed to be in effect. Someone--a court, legislature, or executive--must be empowered to determine when its provisions are relevant, and if so, precisely what they mean. The constitution supersedes the legislature it has created only when, if, and because someone with sufficient power says it does. Even those who insist that there are moral entailments lodged within every statute and legal situation that need only to be sussed out by competent jurists, will have to admit that these "experts" must be granted the authority to find and publish these entailments as new law. Otherwise, as Hilary Putnam might say, "They're just more theory."
So, Schmitt concludes, no matter how imperious any legal proclamation may sound, such "norms" are no more substantial than crusty, moth-eaten papers that disintegrate into powder when touched. Somebody must always decide what is and what is not required by law.
Well then, who gets to decide? The people surely...but if there is disagreement (as there nearly always is), which people? (If we were in a majoritarian democracy, we'd have an answer to this, but alas....) Answering this question is where Schmitt's friend/enemy analysis comes into play. First of all, as may be obvious, where there are disputes, the ultimate decision-makers can only be, let's call them, "the winners," those with the ultimate power to enforce their will. And only they will be able to determine just who they are, who gets to be part of the in-group. We can know, though, that they will be united by their beliefs. Schmitt says that such unity makes them friends, in this sense, a homogeneous group. Those who would deny them their power are perforce their enemies--the "other."
As no norm--say, some supposed "natural law"--constrains this group of winners, they can do anything they want to do. (Not "pretty much anything they want to do" but exactly anything at all.) Their sovereign power is absolute and unlimited--to an even greater extent than Hobbes' Leviathan. It is easy to see why Schmitt's philosophy was found congenial by the Nazi Party.
What responses can be given to Schmitt's arguments? One might try to push anarchism, which, having no interest in state power, can insist on the existence of liberal rights but agree with Schmitt that, since both norms and formal democracy are impotent, there is no way to create lawful state power through their use. Another approach would be to claim that one cannot coherently deny the truth of certain liberal norms at all. One might say, in other words, that as certain truths are "self-evident," no decision made in violation of any of them can be rational. That's a pretty response, certainly. Perhaps the easiest thing to do is simply call Schmitt's position reprehensible. (After all, he embraced Nazism!) Even more convenient, one might just ignore it and let things go on however they happen to be going on. Of course, that approach works best for those who are doing well as things are, those who happen to be living the dream in a limited government maintaining a liberal conception of such rights as the popularly claimed one to personal property. That blessing is, naturally, particularly inviolable as creator-endowed "rights" go.
I myself think there is another approach that can be taken to Schmitt's quite difficult challenges. I will try to indicate its general direction in my next couple of blog posts (and, if I can ever figure out which book(s) to focus on, in my next Hornbook review at 3:16 AM Magazine, perhaps there as well).