[Eugene Volokh] The grammar of Donald Trump tweeting ‘Thanks, Donald!’

The U.S. Consumer Confidence Index for December surged nearly four points to 113.7, THE HIGHEST LEVEL IN MORE THAN 15 YEARS! Thanks Donald!

— Donald J. Trump (@realDonaldTrump) December 28, 2016

Prof. Ben Zimmer (Language Log) reports that it’s vocative self-address, and he offers some historical antecedents. Don’t confuse it with illeism, of course.