Fourteen months ago, when there were still about two dozen candidates in the race for the Democratic presidential nomination, I wrote about the critical ingredient missing from Joe Biden's campaign.
Yep, I'm about to start this article by quoting myself, which is objectively the most insufferable thing a reporter can do. Rest assured, I feel dirty.
But bear with me, because it's in service of an important point.
"Most of the other Democrats running for president have a clear rationale; a genuine reason to vote for or against them," I wrote in June of last year.
"Joe Biden's rationale is ... what, exactly? That it happens to be his turn?
"Mr Biden really, really likes to remind voters that he was Barack Obama's vice president. He often speaks of the Obama administration's record as though it is his own, when everyone knows the American vice president doesn't actually do all that much.
"His pitch essentially boils down to: I was Obama's vice president. You like Obama, and Obama likes me. Therefore you should vote for me."
Those words were true at the time, and they arguably remained so all the way up until the Democratic National Convention this week.
It was never clear why Biden was running for president. He just seemed to think he was next in line.
He was the frontrunner by default; the personification of a moderate, inoffensive Democrat. He spoke endlessly about the achievements of the Obama administration, along with all the obscure pieces of legislation he helped pass as a senator decades ago, but had relatively little to say about his own policy agenda going forward.
Month after month, the Biden campaign meandered like this, listless and directionless, struggling to find a core rationale for electing the guy.
Then America's coronavirus epidemic spiralled out of control, wrecking the country's economy and killing thousands upon thousands of its people.
President Donald Trump reacted by repeatedly downplaying both the threat of the virus and the suffering of his constituents.
"What do you say to Americans who are scared?" NBC reporter Peter Alexander asked him at one White House briefing.
"I'd tell them you're a nasty reporter," came the President's less-than-empathetic response.
Even now, Trump continues to insist the virus is under control. He brushes off America's horrifying death toll, insisting it only looks so bad because the nation does so much testing.
The President has managed to create the impression that he doesn't actually care all that much about the loved ones so many people have lost.
The result of that callousness, politically, is that Trump has handed Biden the solution to his biggest problem.
Which brings us back to this week's convention.
The event was far from perfect, with more than its fair share of stilted speeches and bizarre tonal inconsistencies, but the Democrats will be happy anyway.
Why? Because they successfully cast Biden as a candidate uniquely suited to the moment the US is facing. At last, his candidacy has a clear and unambiguous purpose.
Each of the convention's four days drilled home the same message to the American people – that Biden understands and empathises with their suffering, because he has endured the same sense of loss himself.
That he knows how to heal and rebuild a broken nation, because in the words of his wife, Dr Jill Biden, it's the same way he healed his broken family.
"I understand how hard it is to have any hope right now," the candidate himself said in his speech to the convention on Friday AEST.
"Let me take a moment to speak to those of you who have lost the most.
"I have some idea how it feels to lose someone you love. I know that deep black hole that opens up in the middle of your chest. You feel like you're being sucked into it. And how mean, cruel and unfair life can be sometimes.
"But I've learned two things. First, your loved one may have left this earth, but they'll never leave your heart. They'll always be with you, you'll always hear them. And second, I found the best way through pain and loss and grief is to find purpose.
"Each of us have a purpose in our lives. We have a great purpose as a nation. To open the doors of opportunity to all Americans. To save our democracy. To be a light to the world once again. And finally, to live up to and make real the words written in the sacred documents that founded this nation, that all men and women are created equal.
"Our current President has failed in his most basic duty to the nation. He has failed to protect us. He's failed to protect America. And my fellow Americans, that is unforgivable."
As far as the Biden campaign is concerned, the election is not about policy. It is about something as simple as replacing a President who doesn't care with one who does.
No doubt some members of the Trump campaign would roll their eyes at that sentiment. Usually, most voters probably would as well.
But the convention highlighted an astonishing number of examples of Biden actually practising the compassion he preaches.
We heard from a 13-year-old boy who said Biden had helped him overcome his stutter. We were told about the hours the former vice president spends after dinner, speaking to people who have suffered loss; the letters he sends out of the blue to strangers who have been diagnosed with cancer.
Empathy is a powerful weapon in politics, even more so in the midst of a global disaster. Trump would be foolish to dismiss it. I'll explain why.
Traditionally, one of the three debates before a US presidential election is conducted in a town hall format, with normal voters asking questions of the two candidates instead of professional moderators.
Let's assume such a debate goes ahead this year, despite the pandemic, with social distancing measures in place.
What is going to happen when a member of the public stands up, tells Trump they lost a loved one to the virus, and asks the President why he failed to protect them? Why he kept insisting the virus would disappear, and pushed for states to reopen their economies while daily infections were still in the tens of thousands?
Is Trump going to call it a nasty question? Is he going to accuse the voter of being biased against him? Will he tell them the virus is actually under control, and that the death of their loved one somehow doesn't count because the US does a bunch of testing?
I honestly have no idea what his answer would be. We have no guide here, because Trump never interacts with a member of the public who doesn't already support him.
Sure, he'll fly into a swing state for a rally every now and then, but what does that tell us? He typically spends an hour or so on stage, bathing in the adulation of his fans, then hops back on Air Force One and returns to the White House.
The only hostile questions Trump ever faces come from reporters. And you can't slap down a grieving member of the public by ranting about "fake news".
I can tell you how Biden will react to that question.
He'll give the grieving voter some variation of that excerpt from his convention speech above. He will talk about the death of his first wife Neilia and their one-year-old daughter Naomi. He'll explain how he kept going after his son Beau's death in 2015; how he found purpose in life again.
For so long, Biden's failure to fully articulate that purpose was a gaping hole in his campaign. Americans didn't know why he was running. Now they do.