Gene Callahan has some good thoughts here. He writes:
"Dan Klein claims: "One’s ideological views – that is, the pattern of positions one tends to take on important public-policy issues – run deep and change little."
Well, Dan is not using the word "ideology" in the same way I do. And that's fine: I can get different definitions than my own. But in my case the claim is simply empirically way off: My views have changed dramatically at least five times in my life: from conservative as an adolescent (I used to watch Firing Line religiously at age 12!), to pretty far left by my mid-twenties, to neoconservative in my mid-thirties, to mild libertarian a few years later, to libertarian anarchist, and finally, to a understanding that holds that ideologies themselves are the main problem with contemporary politics.
I like to believe that this is a result of a willingness to think things all the way through again and again, changing my beliefs as required by such re-thinking. My critics will probably say it is just evidence of some personality disorder. I figure the odds are 50-50 as to who is right."
I probably lean more towards Gene's presuppositions about the meaning of "ideology". Dan Klein's definition here simply refers to a consistently held position. Of course, consistency can be well reasoned and empirically supported. I usually think of being "ideological" as adhering to ideas because of a desire to make your positions "fit" with some larger, coherent worldview.
Gene also links to a thoughtful post by Rod Dreher on the topic.
Ideology's primary cost, of course, is it's inflexibility. Internally consistent worldviews are a dime a dozen. The harder part comes in when you realize that consistency with the external world is a lot harder to establish, and often requires flexibility in foundations and conclusions.
Partisanship is of course the worst sort of ideology. Inflexibility when it comes to the ideas you hold - a determination to "fit" what you think with an internally consistent, pre-fabricated worldview - is bad enough. When you then substitute an articulated worldview for a party, you don't have much less to stand on. Liberals who never question a Democratic president. Republicans who blame Democrats for what they lauded in Republicans. Libertarians who will fawn over Ron Paul at the same time that they project their hero-worship onto others, etc. Parties are useful things. At a time when nobody on "the other side" seems palatable, one can be relieved that the party institution at least maintains a center of semi-sane gravity. But anything much beyond that appreciation seems dangerous.