“The Celebration Parallax may be stated as: ‘the same fact pattern is either true and glorious or false and scurrilous depending on who states it.’ In contemporary speech, on any ‘controversial’ topic—or, to say better, regime priority — the decisive factor is the intent of the speaker. If she can be presumed to be celebrating the phenomenon under discussion, she may shout her approval from the rooftops. If not, he better shut up before someone comes along to shut him up.”