- It was on this day four years ago - at the exact same stage of the last US presidential cycle - that Mr Trump made his announcement: he would, for real this time, run for the highest office in the land.
- The property mogul and TV host was the 12th candidate to come forward to try to claim the Republican Party's nomination.
When Donald Trump descended the golden escalator to announce his run for president, none in the sceptical media pack below could have imagined he would win.
It was on this day four years ago - at the exact same stage of the last US presidential cycle - that Mr Trump made his announcement: he would, for real this time, run for the highest office in the land.
The property mogul and TV host was the 12th candidate to come forward to try to claim the Republican Party's nomination.
If the Washington establishment was sceptical, it was because this was not the first time he had floated a run for the White House, only not to follow up on his own speculation.
Many of the reports that day reflected those doubts. Many of them, employing a degree of mockery rarely used in news, denigrated his performance at the podium inside the gilded Trump Tower. Some of them, though only some, focused on his claim Mexico was sending "rapists" over the border.
What did commentators that day fail to understand about the man who would be president? And what did they get right?
'He seems like he means it' - BBC News
What we said in 2015
"Donald Trump is actually running for president," our North America reporter Anthony Zurcher wrote. "Few people expected it to happen - he's gone through the motions many times before - and his political rants up until now have been roundly derided as a joke. But this time he actually said the words, and he seems like he means it...
"He's already proven a willingness to take swings at his opponents. Jeb Bush and Marco Rubio 'don't have a clue', he said in his announcement speech. 'How are these people going to lead us?' he asked.
"If he says that enough times during a debate - or in a multi-million dollar television advertising spree - a lot of people are going to stop laughing and take notice. And that's probably just what Mr Trump wants."
How does that view look now?
"Donald Trump got people to take notice all right, but I never thought someone with negative ratings as high as his could capture the nomination," Anthony writes in 2019. "I figured the Republican establishment would coalesce around an alternative - and it never really did.
"There's a theory that Trump's presidential campaign was a publicity stunt gone awry, a real-life version of The Producers, where an enterprise designed to fail became an accidental success.
"Only Mr Trump knows the truth, but his pugilistic brand of politics capitalised on a moment in American history when just enough voters were fed up with the status quo to take a chance on an unlikely outsider."
'Much-needed seriousness' - Democrats
What they said in 2015
"Today, Donald Trump became the second major Republican candidate to announce for president in two days," Democratic National Committee (DNC) spokeswoman Holly Shulman said in a statement that proceeded to lay on the sarcasm in spades.
"He adds some much-needed seriousness that has previously been lacking from the GOP field, and we look forward to hearing more about his ideas for the nation."
How does that view look now?
Neither the DNC nor Holly Shulman responded when asked how they viewed those comments now.
Trump may have an opening - Washington Examiner
What they said in 2015
Days before Mr Trump's announcement, Byron York wrote in the conservative Washington Examiner that the mogul could appeal to Republican voters tired with the direction the party was taking.
"It's been clear for quite a while that some conservative voters are so disgusted with the GOP that they would entertain the notion of a third party," he wrote.
"If he pursues a race seriously, Trump could win the support of those I've-had-it-up-to-my-eyeballs voters. Their concerns aren't a joke. If Trump doesn't address them, somebody else will."
How does that view look now?
The fact Mr Trump was not an establishment politician, and could shake up the system, was a factor his supporters went on to regularly cite for why they loved him.
Here's what some of his supporters told us in summer 2016: