President Obama’s speech in Tucson tonight seems to have won nearly universal praise. I suspect it will be remembered as one of his best moments, almost regardless of what else takes place during the remainder of his presidency.

As I’ve mentioned before, this was the first tragedy of this kind that happened in the Twitter Age. From almost the first moment that word about the massacre broke, people had all sorts of theories — often expressed in no more than 140 characters — about the shooter and his motivations.

Some of the theories — such as those that tried to place Jared L. Loughner somewhere on the traditional left-right political spectrum — ran the risk of being presumptuous on the basis of what we knew at the time. And indeed, as more has become known about Mr. Loughner, some of them do not seem to be well supported by the evidence.

Still, nobody seemed to have been chastened much. Instead, after Sarah Palin’s videotaped statement — I would recommend The Washington Post’s Jennifer Rubin for a judicious take on the particulars of it — the discourse about the tragedy almost seemed to be lapsing into self-parody.

The cynic in me wants to say that, in this context, this was a relatively easy speech for Mr. Obama to deliver (in a political sense rather than an emotional one). Nobody seemed to be playing the role of the adult in the room or moving us toward closure, which provided Mr. Obama with an opportunity to do so. Mr. Obama played that role very well tonight, although I suspect that almost all of his predecessors would have done the same.

At the same time, Mr. Obama’s decision to focus in some detail on the victims of the tragedy — not just Gabrielle Giffords but the others, and not just in a perfunctory way but in one that seemed heartfelt — showed a lot of dexterity for the emotional contours of the moment. And at times, his speech showed an intellectual dexterity as well. This passage, in which Mr. Obama refocused the discussion about civil discourse without trivializing the tragedy, struck me as especially strong:

And if, as has been discussed in recent days, their deaths help usher in more civility in our public discourse, let’s remember that it is not because a simple lack of civility caused this tragedy, but rather because only a more civil and honest public discourse can help us face up to our challenges as a nation, in a way that would make them proud.

I’m going to avoid speculating for now on the political implications of the speech, except to say that much of what takes place during a president’s term, and much of what ultimately affects public perception about whether it was a success or a failure, stems from unplanned contingencies that are ultimately outside of his control. But certain types of contingencies suit the temperaments of certain types of presidents especially well, and this seems to have been one such case for President Obama.