As the debates over the War and the economy rage on over the internet, the accusation often raised is that people have made a religious belief system out of their politics. Conservatives are often accused of having a cult-like belief in the free market. Leftists, of course, have turned their entire political system into a quasi-religious belief system that defies or denies quite a bit if reality. The postmodernists tacit agreement is apparently that only the true believers can understand; having denied all basis for truth one must be a leftist in order to know the truth, a truth that, to the leftist, is left unspoken and therefore unchallenged.
In the context of such debates most of the time "religious" means "deeply held, pre-rational beliefs with great emotional appeal."
All of us of can be said to be guilty of having such beliefs. Indeed, it might be argued that we need to have such beliefs as a necessary requirment for emotional stablity. (The quesition of what happens when people apparently have no such beliefs is the topic for another essay, but suffice to say that they are fairly dysfunctional.)
It's usually easy to spot these beliefs even in people who regard themselves as free of them. For example, ask the average secular modernist liberal to defend the rationality of egalitarianism.
Where it gets creepy is when people start denying that they are arguing out of such a basis when they clearly are; i.e., when they are clearly closing their eyes to reality in an untoward fashion in order to hang on to emotionally appealing core beliefs.
And, of course, there is no arguing with such people. There is no point in a dialogue unless it is to sway the undecided bystanders.