Been thinking quite a bit about that "crusade" image -- actually even before Bush actually uttered it, and then took it back.
The premise to this question requires that I first elaborate my thoughts on organised religion. Borrowing from Obi Have's proposed definition of elements required for religion from a different thread:
1. Provides individuals with personal meaning, and the conceptual tools to cope, grapple, and come to terms with their eventual death. This is what emilsson alludes to as the "transcendent function" of religion.
2. Provides individuals with the grammar and rules of life; e.g., it teaches people values about how to interact and behave with others. Organized religions serve this function (10 Commandments), but so does 'secular morality' and so does "civil religion."
I expand upon this and suggest first that coming to terms with death correlates exactly with understanding, identifying, or otherwise simply labelling the point of (sentient) life; and that the primary additional requirement specifically for "organised" religion, as opposed to personal spirituality, is a structure which allows individuals to share the above defined value system, and which may be questioned (but only within that structure: the questioning may not challenge the foundations of the structure).
It is worth specifying that these points identify organised religion as a "belief system". Although the tenets are often claimed to be based on some form of absolute knowledge, those following the tenets rarely lay claim to that absolute knowledge, but accept and follow those tenets as an article of faith.
Within these three points (why life, social values and mores, societal structure): I suggest that there is fundamentally no difference between what we commonly identify as "organised religion" and
* partisan politics
* identity-defining economic systems, such as capitalism and communism
* some racial, ethnic, or professional superiority systems
* a faith in procedure and/or law
* Science and the Scientific Method
(Whether or not this premise holds true is certainly arguable -- but I would ask that we open a new thread to argue it.)
Labels such as "secular humanism", "New Age", and "atheism" could be considered spiritual and possibly even religious, but I do not consider them "organised religions" because of the lack of any consistent societal structure, however limited, supporting the first two points. This could change.
I would also argue that the power of those structures which I do enfold within "organised religion" -- but which their practitioners normally do not -- is significantly multipled precisely because we often do not recognise that they draw much of their power from the basis of a shared belief system. Much of the West (with the notable exception of identifiable "Bible Belts", as well as that curious dichotomy that is the modern United States) has become to some extent "immunised" against religion-as-word: having learned to give unto Caesar those things which are Caesar's, and unto God those things which are God's.
What happens when Caesar, or the position of emperor, or the idea of Rome, has taken the place of God?