His father's side of the family is from Kosovo. As a child, Djokovic was terrified by the NATO warplanes that bombed Belgrade in 1999 to stop Serbian armed offensives against ethnic Albanians in Kosovo. ("When I hear a big noise even now, I get a little traumatized.")
Critics seized on Djokovic's comments to the rally as evidence of the nastiness lurking beneath even the acceptable face of Serbian patriotism.
"I don't want to expose my opinion on that too much because they will use it against me," he said warily, when asked about the episode in a subsequent interview.
For the moment, he's happy to keep on expressing how proud he is to be Serbian without getting drawn into uncomfortable specifics. And his countrymen are happy to project onto him their aspirations for a New Serbia.