I saw Somin's post, CK. You're correct that he's typically viewed as a conservative (really libertarian). I didn't think he particularly engaged the arguments on the other side much though. For a good week, there have been vigorous responses available to most of the arguments he used there.
For my part, I think what Obama did is in a legal gray area, and certainly wouldn't (for example) support impeachment or say that he clearly violated the Constitution. What I do think is that he clearly damaged our institutions. Executives using unprecedentedly broad powers contra Congress's will while acting in legal gray areas, especially in an age when the executive is already far too expansive, is bad for the country, and I think Obama recognized that as late as last year. I'm sad that he forgot it, especially because he (very clearly) torpedoed any hope of getting this or anything else done for the next two years legally.
Bush spent much of his Presidency staking out ground in legal gray areas, and Obama has staked out large new ground today. It was terrible for the country then, and it's terrible for it now (even though the actual actions he's taken are things Congress should, in some form or another, probably do). People of any given day tend to care more about the domestic or foreign issues facing the country than the institutions that enact and execute those issues, but most of the time, the latter is far more important to the long-term health of the country.