Carl Schmitt argued that without a friend-enemy distinction there was no 'political'. Increasingly that division is rotating around the distinction between reason and irrationalism. Reason is often construed as a political outlet for liberalism.

Conservapedia recently challenged scientific data for a bacterial experiment. From the article:

Of course, that lack of understanding [scientific illiteracy] might be expected from someone who seems to believe that there are distinct conservative and liberal forms of science.

Still, you can sense the beginnings of a response to the fact that the situation may be spiraling out of Conservapedia's control.

When a contributor suggested the exchange was making the site look bad, the response indicated that the any problems could be dismissed as a case of biased perception: "What sort of Liberal defeatism are you bound up in, and why do you assume, without examining the facts of the matter, that this has not gone well?"

The division is not really scientific, it is political with the friend-enemy distinction being enunciated clearly. Barry Ritholtz has a similar issue with how the economy is portrayed through media:

We have heard longstanding charges of liberal media bias, going all the way back to Spiro Agnew's Nattering Nabobs Negativism (September 11, 1970). Whatever validity that Trojan horse might have ever had has now jumped the shark. ...

Indeed, the bias is precisely the other way -- between reality and ideological absurdity

It is too easy for those immersed in irrationalism to discard reason, data or rational methods and explain away an inconvenient world-view. Under liberalism and the dominance of the individual as a political entity the debate, too-and-fro of politics is supposed to establish a principle of the least dissatisfaction within constitutionalism.

Liberalism is intended to diminish the foe within, or the enemy of the state, by elevating the individual above the state. The friend-enemy distinction allows for the justification and establishment of the state of exception where the state can act in a manner that is repugnant to the doctrine of inalienable political rights. Effectively placing an individual outside of the judicial order.

Arguably the danger in the friend-enemy distinction is that it aids an environment where the executive can claim emergency and operate under a state of exception.