It isn't topical anymore but a couple years ago getting an American liberal's take on the Dubai Ports World controversy worked pretty well. Also, progressive criticisms of the Bush administration for not implementing more aggressive cargo inspections and airplane security were pretty much just about getting in shots at the administration and not based on evidence.

Last year's debates on bailouts for the automobile and banking sectors struck me as mostly consisting of political signaling with only a handful of people who actually had any idea what they were talking about. You'd see people arguing either side without actually making any reference to any of the economics involved. I.e. "We need to make sure these people don't lose their jobs!" versus "You're just trying to help out your fat cat friends!".

Getting someone on the center-left to admit certain advantages of free trade and market economies probably works as well. The brute opposition to "sweatshops" without offering any constructive policy to provide the people who work in such places with alternatives strikes me as another good example.

It's a little harder for me to do this for the American right-wing since a sizeable portion (definitely not all of it, just an especially vocal part) of it appears to hold their positions for exclusively non-evidential reasons. Some of these reasons don't event appear to have propositional content. (Maybe conservatives see the left this way, though. It might just be that I'm too far away from the right-wing to see this clearly).

A conservative's position on industry subsides- agriculture, textile, sugar etc. is a probably a decent indicator, though. I'd say immigration but the people who oppose it might have good reasons given their terminal values.

A lot of times you can tell when someone holds a position for political reasons just by their diction. It is a really bad sign If someone is using the same phrases and buzzwords as the candidates they support. This reminds me: A little over a year ago the college Democrats here held a debate for the Democratic Presidential Primary. Each candidate was represented by a student who was supporting that candidate. I thought it had potential since being unofficial representatives the students would be comfortable leveling some harsh criticisms and really diving into their reasons for supporting their candidate. The actual candidates are always too afraid of screwing up or alienating someone to diverge from their talking points. What actually happened isn't surprising once you think about the kind of people who are heavily involved in the college branches of political parties (especially at my university). If you haven't guessed it, what happened was this: Every student representative sat on the stage reciting the very same talking points their candidate was already using to dodge criticisms and spin issues in the real debates. It was like a horrifying training session where students learn to ignore evidence, reason in favor of political hackery and bullshit.