These arein sections talking about recess appointments in general. The pro forma section consists of just a few sentences.
More than a few sentences, and it's fairly clear that Harry Reid was the first to do it. Until I see an example of a pro forma session having been used to block recess appointments before Harry Reid did it, the two sources I cited are pretty good evidence that he was probably the first.
Again the context and manner make it unclear whether they are referring to the use in accordance with this specific and temporally recent Justice Dept. brief. The ambiguity involved does not satisfy me that it is historically conclusive.
I don't see an ambiguity. Also, footnote 25 clarifies it further:
It appears that this practice was considered, but not implemented, during the 1980s and 1990s. In response to certain recess appointments by President William J. Clinton in 1999, one Republican Senator reportedly stated, “‘What we can do—if they’re appointments that he should not make—is just not go into recess .... We’ll just go into pro forma. You’re in session, theoretically, but there’s no votes’” (Dave Boyer, “Clinton Warned Against Recess Appointments; GOP Senators May Not Adjourn,” Washington Times, November 5, 1999, p. A1). In remarks on the Senate floor, the Senator indicated that a threat of this practice had been part of recess appointment negotiations in 1985 between Senator Robert C. Byrd and President Ronald W. Reagan: “He [Byrd] extracted from him [Reagan] a commitment in writing that he would not make recess appointments and, if it should become necessary because of extraordinary circumstances to make recess appointments, that he would have to give the list to the majority leader ... in sufficient time in advance that they could prepare for it either by agreeing in advance to the confirmation of that appointment or by not going into recess and staying in pro forma so the recess appointments could not take place” (Senator James M. Inhofe, “Recess Appointments,” remarks in the Senate, Congressional Record, vol. 145, part 163 (November 17, 1999), p. 29915).
The quotes in the footnote don't make sense if the tactic had been used before, and the footnote explicitly states that it was never implemented during the 1980's and 1990's.
Although I've seen plenty of sources that have mentioned Harry Reid's use of pro forma sessions during the Bush administration, none have mentioned any earlier use of it. And two were fairly clear that Harry Reid was the first.
-Bri