There's simply no Constitutional support for that at all. The clause about recess appointments is in Article II, for whatever that's worth (that is, the article about the president, not the Congress). It just talks about "the Recess of the Senate." That's it. There's no definition at all about what "counts" as a recess, or whose job it is to say what counts.The word "recess" only comes up one other time in the Constitution, in a (now-obsolete) similar clause about state legislatures and U.S. Senate appointments. There's nothing at all about who gets to define recess.
Here's what Yoo says:
President Obama is making a far more sweeping claim. Here, as I understand it, the Senate is not officially in adjournment (they have held “pro forma” meetings, where little to no business occurs, to prevent Obama from making exactly such appointments). So there is no question whether the adjournment has become a constitutional “recess.” Rather, Obama is claiming the right to decide whether a session of Congress is in fact a “real” one based, I suppose, on whether he sees any business going on.
This, in my view, is not up to the president, but the Senate.
This may be Yoo's position, but it would be a break with precedent. As You knows (since he refers to it in his article), the current three-day minimum standard is derived from a Clinton-era Justice Department opinion. Not the Senate. The Justice Department.
Of course, Yoo and Noah could still be correct that the decision should rest with the Senate. But the Senate has never, as far as I know, made any such determination. There are various minor technical differences between the various times that the Senate is out of session (intersession, between different Congresses, overnight/weekend intrasession, and longer intrasession), but the the Senate generally does not use different vocabulary for them, and certainly does use the word "recess" for the breaks relevant here. The Senate does not, in any official way, announce that they are now in recess for the purpose of the Constitutional appointments clause.
Moreover, and this is why the point I made yesterday is I think relevant: even if it were up to the Senate, we know that the Senate Majority Leader, and presumably the majority of the Senate, support the president's recess appointment. Surely Yoo doesn't believe that the Speaker of the House has a Constitutional role to play in determining whether a recess counts as a "Recess of the Senate"?
Granted, I wouldn't say that it must be a real Recess just because the president and the Majority Leader agree that it is; they could certainly be wrong, either honestly or cynically.
The actual issue here -- how long does a recess of the Senate have to be before it counts as a Recess of the Senate for these purposes -- is legitimately contentious, because we don't really have any guidance for what "recess" means in this context. That's why I'd like to see exactly what the WH is relying on (as Kevin Drum said yesterday). And while I believe I agree with the decision, I think there's plenty of room for legitimate disagreement on substantive grounds. But as far as the procedure, I just don't see it as a problem for the White House to have its own interpretation of a vague Constitutional clause in cases where precedent doesn't apply. There's no reason for the president to defer to Congress on the definition.