I know where you're coming from, but I still don't think "empirically" best applies to liberals. Conservatives aren't claiming theoretical wisdom from out of thin air, but deriving their claims from experience--empiricism. So far as it goes, I think conservatives do have a longer-term framework in the experience they draw from--historical awareness!--but formally, when he takes the time to revise before posting, a Krugman will claim that he has just as many long-term empirical data points as does a conservative. I think both camps are formally equally empirical, and liberals are practically more short-term in their empiricism; but calling liberals more empirical smacks (in your case) of a private jargon--as opposed to when liberals say it, when it's just self-congratulation.
I think I'm going to kick strongly against "Conservatives thinking more long run have to rely more upon theory." It's certainly not our self-understanding--we take ourselves (we=some largish number of people who self-identify as conservative) to be anti-theoretical, to rely on a much thicker source of experience--history, tradition--to inform our judgments. One of the interesting winkles is whether "experience" should only be personal experience (a liberal tendency, I would say) or allows the experience of the past as well (conservative!) On this economic front, a great deal of experience has hardened into free-market theory, so it's a nice question as to whether a free-market instinct is experiential or theoretical in nature. I'd say there are a lot of people who take free markets as a theoretical truth; they may be political allies, but I think they are not my philosophical or dispositional kin. (No True Conservatives!--but I break bread with them, so perhaps I shouldn't insist on the point.)
Liberals may rely more on short-term data, but I don't think that makes them more empirical than conservatives who ruminate about Austrian economic policy in 1873, or the pot production of the Roman Empire.
Some of this turns on "data that is relevant." I think you are implicitly defining Roman pot production as irrelevant, which I think assumes the question at issue.
FLG agrees he might have private jargon issue going on here and definitely needs to work out a more lucid articulation. Perhaps, rather than theoretical, rational versus empirical is a more accurate explanation.
Nevertheless, theories aren't created ex nihilo. They necessarily are born out of some set of observations or experiences, especially when we are talking about political and economic theories. Moreover, all arguments require the marshaling of evidence. FLG thinks that short-term analysis is more conducive to empirical and in particular quantitative evidence.