The President reminded his supporters of Ms Clinton's infamous "deplorables" gaffe.
"Do you remember this? They called us deplorables. I think Hillary Clinton made a big mistake with that speech," he said.
He accused her of colluding with Russia and turning the US State Department into a "pay-for-play cash machine" when she was secretary of state.
"We went through the greatest witch-hunt in political history. The only collusion was committed by the Democrats, the fake news media and their operatives, and the people who funded the phony dossier — Hillary Clinton and the DNC."
He even hinted his Justice Department could still prosecute Ms Clinton over the private email server she ran as America's top diplomat.
"Lock her up! Lock her up!" the crowd chanted, as though transported back to the heady days of November 2016.
Why bother coming up with new material when your fans love the old hits so much?
But as Mr Trump prepares to take on Joe Biden, or Elizabeth Warren, or any of the other 20-something Democrats who are actually running for president, he might want to roll out a more relevant campaign message than: "How bad is Hillary?"
This focus on Ms Clinton yesterday was not a surprise. It was consistent with Mr Trump's behaviour since the day he was inaugurated. You don't need to spend much time combing the President's Twitter feed to find references to "Crooked Hillary's emails".
But as with much of what Mr Trump does, we should take the time to point out this is not normal behaviour.
While most US presidents tend to focus on the job after winning power, at least somewhat humbled by the responsibility on their shoulders, he would rather waste his energy rehashing old grievances.
Washington Post columnist Dana Milbank, citing analytics company Factba.se, reports Barack Obama referred to George W. Bush or John McCain once every three-and-a-half days at this point in his presidency.
At the time, Republicans criticised Mr Obama for spending too much time blaming America's problems on his predecessor. And they were right!
Mr Bush was even more sparing, mentioning Bill Clinton or his vanquished 2000 opponent Al Gore only once every 63 days.
By comparison, Mr Trump has a pop at Ms Clinton or Mr Obama, on average, once every nine hours and 20 minutes, constantly relitigating arguments that became irrelevant to most people years ago.
It's the equivalent of Scott Morrison posting two snarky tweets about Julia Gillard every day. Sure, she's been retired from politics for years now, but remember that time she promised not to implement a carbon tax?
Actually, that's not quite right. Because in the overwhelming majority of cases, Mr Trump is not focusing on Ms Clinton or Mr Obama's policies, but on the ways in which they have made him feel personally slighted.
Mr Obama spied on him. Ms Clinton got away with crimes. The media, and in Ms Clinton's case the FBI, never went after either of them like they go after him.
Those statements might not be entirely consistent with the facts, but Mr Trump believes them, and he obsesses over them.
The President spent 76 minutes on stage yesterday. Occasionally, he touched on a subject voters would actually care about, like unemployment or immigration — the wall is still going to be built, apparently, though the whole "Mexico will pay for it thing" is not said quite so often or loudly these days.
A huge chunk of his time, however, was devoted to reminiscing about his win in 2016 and whining about being treated unfairly.
"If you want to know how the system is rigged, just compare how they came after us for three years, with everything they had, versus the free pass they gave to Hillary and her aides after they set up an illegal server, destroyed evidence, deleted and acid-washed 33,000 emails, exposed classified information," he said.
That's just one example. There were plenty of similar ones to choose from.
The first thing to say about this quote is that it's nonsense.
You can argue Ms Clinton should have been treated more harshly, but she certainly didn't receive a free pass.
The FBI announced it was reopening its investigation into her during the final weeks of the election — an unprecedented move that undoubtedly pushed voters towards Mr Trump. The email server may well have cost Ms Clinton the election.
And the Mueller investigation was not, as the President likes to claim, an "illegal witch-hunt" run by "angry Democrats".
It was set up by Mr Trump's Republican deputy attorney general and led by Republican Robert Mueller. Why? Because Mr Trump fired a Republican FBI director and lied about why he'd done it.
This might seem rather basic, but the whole point of calling something a witch-hunt is witches aren't real. The Mueller investigation uncovered very real criminal conduct and drew guilty pleas from several members of Mr Trump's campaign staff.
But forget the merits, or lack thereof, of Mr Trump's argument. The broader problem is he has no good reason to still be hung up on Hillary Clinton anyway.
"The FBI was mean to me," is not an argument for re-election. "The media is mean to me," isn't either. And "Hillary is awful," might have worked well for Mr Trump in 2016, but she is not on the ballot this time.
So stop talking about her, Donald. It's getting weird.
This article was first published on news.com.au.
