The crowd erupted into a chant of "LeBron James sucks".
"What a crowd. What a crowd!" Trump remarked.
The NBA's offence here was to let its teams protest in solidarity with Black Lives Matter.
The league's ratings were significantly down this year, though I don't think we should feel too badly for LeBron, who won his fourth championship.
Trump's riff drew a lighthearted response from Chicago, which was of course the home of Michael Jordan.
Next up on the hit list was Lady Gaga, who campaigned with Joe Biden today.
"Now he's got Lady Gagaaa. Lady Gagaaa. It's not too good," said Trump.
The crowd jeered in response.
"I could tell you plenty of stories. I could tell you stories about Lady Gaga. I know a lot of stories about Lady Gaga.
"And Jon Bon Jovi! Every time I see him, he kisses my ass. 'Oh, oh, Mr President.' He'll get something out of it, just like everyone is.
"But you know what happens? You bring in some of these – by the way, we draw much bigger crowds than these people. But you know what happens? He'll sing a song or two, and then he'll leave, and the crowd will leave, and sleepy Joe's up there talking. He then namechecked more celebs, pronouncing Beyonce's name is bizarre fashion.
"That happened to Hillary too, right? They got Beyonsee. And they got Jay-Z."
Trump has said that "we're going in with our lawyers" as soon as the polls close in Pennsylvania and spoke ominously about the Supreme Court decision to grant an extension to count the votes after Tuesday.
"They made a very dangerous situation, and I mean dangerous, physically dangerous, and they made it a very, very bad, they did a very bad thing for this state," Trump declared.
He said of Pennsylvania's Democratic Governor Tom Wolf, "Please don't cheat because we're all watching. We're all watching you, Governor."
- Additional reporting, NZ Herald/AP
