Today, Glenn Greenwald has written a long post touching on this subject. Glenn's attention focuses on the flip side of this coin, self-styled conservatives who are not conservative, or at least who do not apply the principles which they consider conservative consistently. The example Glenn pulls to make this point is an article from Free Republic which denounced the Clinton adminsitration's use of the FISA courts as a dangerous threat to liberty. These same people at Free Republic are now defending the Bush administration's choice to bypass the FISA courts and engage in surveillance with even less oversight than that which the previous administration did.
This is difficult to understand, but it makes sense if one applies the interpretation of conservatism that was put forth by F.A. Hayek, who in the essay "Why I'm not a Conservative," writes
In general, it can probably be said that the conservative does not object to coercion or arbitrary power so long as it is used for what he regards as the right purposes. He believes that if government is in the hands of decent men, it ought not to be too much restricted by rigid rules. Since he is essentially opportunist and lacks principles, his main hope must be that the wise and the good will rule - not merely by example, as we all must wish, but by authority given to them and enforced by them. Like the socialist, he is less concerned with the problem of how the powers of government should be limited than with that of who wields them; and, like the socialist, he regards himself as entitled to force the value he holds on other people.When Hayek states that the conservative "lacks prinicples" he does not mean that the conservative lacks moral values. What he means is that conservatism, by its nature of being a reactionary force, lacks a coherent philosophy from which to derive political positions, and is thus opportunist in that it will seize on whatever tactic will achieve its ends. If we take this description of conservatism to apply to the individuals Greenwald refers to, then the apparent contradiction of approving an action for one President, and disaproving it for another, disappears.
As I've previously written, I consider one of the biggest obstacles to constructive debate is the way in which we use terms to label people, and I suppose I should take the opportunity to reiterate my third suggestion for elevating the level of political discourse:
Conservative or liberal may be used as adjectives to describe persons or ideas, but only within the context of what the words actually mean, not what they have come to be negatively associated with. Under no circumstance should either term be used as an insult.