First, "social engineering" is like any other convenient shorthand: it saves space and explanation, but in so doing probably over-simplifies a larger point.  Just as one can support Darwinism without supporting social darwinism & eugenics, so too can one be opposed to sloppily-directed government welfare without being opposed to social policy.

As I've used the term, "social engineering" is intended to represent the idea that government can use funds to support social projects that are not directly related to the source of funds.  This isn't a left or right issue, as both parties are equally guilty of it - they just have different pet issues.  And from an economic perspective, I maintain that activities that connect costs and benefits tend to drive pretty efficient behavior.  Activities that steal from Peter to pay Paul drive pretty inefficient behavior.  (Note that this is true regardless of what one thinks about Peter's right to his money or Paul's social need - it's just an observation on efficient capital allocation.)

To wit, if we take money from income tax revenues and use it to subsidize the cost of oil (e.g., maintaining troops in the middle east, subsidizing domestic exploration, etc.) it has the effect of making gasoline appear artificially cheap.  Which slows the rate at which competitors to gasoline can come on the market.  Which means that as a society, we are paying for the military consequences of our gasoline addiction out of one pocket and the environmental consequences out of the other.  (Or, as Jim Woolsey has phrased it, we fund both sides of the war on terror.)  This is social engineering as far as I'm concerned and it's pretty bipartisan.  Whether you're for tax breaks to oil majors or against the regressivity of higher energy costs, this is the kind of social engineering that gets support from everyone... which is why it's so hard to get rid of.  But there's no getting around the fact that a part of the reason we can't break from fossil energy more quickly is because we subsidize the hell out of fossil energy, and then force alternatives to compete on their merits.  Presumably, we're all in agreement so far?

Now let's come back to my beef with social engineering in our GHG policy.  It is fundamentally the same issue, just with different actors in the role of Peter and Paul.  We put a price on carbon, compelling emitters to pay for their sins.  So far, so good.  But then, instead of spending that money to reduce GHG emissions, we distribute it amongst a whole litany of social causes.  Wildlife conservation.  Estuarine recovery.  LIHEAP.  Worker Training.  National Security.  To varying degrees, these are all good causes.  But so is making sure that poor people don't have to choose between food and energy this month.  And at core, those social causes have nothing to do with lowering GHG emissions.  So, in exactly the same way that our tax policy skews investment away from alternative energy sources, so too will this particular GHG policy skew investment away from GHG reduction.  

So the question isn't whether or not there are worthy social programs out there.  The question at hand is whether or not a given GHG policy is structured to reduce GHG emissions.  Because I'm pretty sure that's the goal of the policy, and 10 years out, we're not going to be evaluating this bill on the basis of how many piping plover habitats it protected.  And the exact same economic logic that compels us to admit that our tax policy is skewing investment decisions away from clean energy will also have to conclude that our GHG policy is skewing investment decisions away from GHG reduction.  

To be fair, if we believe that the most important thing to do is to fund LIHEAP, the Wings Across America program and forest fire protection, I'm OK with that - just don't dress up those causes in a GHG policy cloak.  

All elected officials practice social engineering.

For Dean Baker's indictment of Republican social engineering read this.

http://www.conservativenannystate.org/