Five years ago, at the White House Correspondents' Dinner, President Obama talked about Donald Trump in a prime-time speech for the first time. He did not bother refuting Trump's prevailing argument at the time — that Obama is not American — because doing so would validate it. He instead gave Trump's ego a very public rhetorical swirly in front of many of the glamorous showbiz types and powerful people Trump admires, the only type of warfare that has ever worked against the perpetual commotion machine. It was devastating.

"Trump’s humiliation was as absolute," Adam Gopnik at The New Yorker later wrote, wondering what role this night played in the growth of the Donald's political power, "and as visible, as any I have ever seen." The audience even laughed at the line, "We all know about your credentials and breadth of experience."

"Say what you will about Mr. Trump," Obama said in conclusion, "he certainly would bring some change to the White House." A picture was then shown of the executive mansion, the columns replaced with pillars of gold, a new towering addition perched on top, and "The White House" written in magenta neon.

After he gave his last convention speech as president, it was clear that Obama's calculus on Trump had changed. Twelve years after the country first met Obama during his career-making 2004 convention speech, there is not one America, and one of the ideological fault lines separating us splits those who still think Trump is a joke and those who cheer when you say, "he certainly would bring some change to the White House." At face value, the man is still worthy of mockery, Obama seemed to say on Wednesday, but Trump's arguments have captivated so many that they must also be taken seriously. And a new strategy must be found if you're going to convince his could-be supporters to rethink their votes.

But how do you take on an opponent once considered so harmless that you could throw rotten tomatoes at him and not expect any repercussions? Just like Trump's Republican primary opponents, it's clear that the Democrats aren't quite sure. Many speakers at the DNC were tasked with different offensive maneuvers, perhaps in an effort to see which worked best before sharing the cream of the crop with the rest of the nation this fall. After a video showing how Trump mocked a reporter's disability played, a disability rights advocate told the audience, "Donald Trump has shown us who he really he is. I honestly feel bad for anyone with that much hate in their heart." An endless parade of other videos featuring Trump's own ill-chosen words were shown. Vice-presidential nominee Tim Kaine mixed some old-school Trump mockery — skewering his dependence on the phrase "believe me" via an endearingly bad impression — with a peek behind those words, noting that there was nothing holding them up but hot air. Joe Biden lambasted Trump for his lack of empathy and showed that anger could not only propel Trump forward, it could challenge him, too, as people push back against his apocalyptic picture of the country. The DNC put a conservative independent, Michael Bloomberg, onstage and had him basically call Trump a con artist.

Other arguments against Trump felt familiar, if stripped of the ideological underpinnings that were the most useful way to emphasize the differences between parties in a world without this year's GOP nominee. Back in 2012, President Obama said, "our friends down in Tampa at the Republican convention were more than happy to talk about everything they think is wrong with America. But they didn't have much to say about how they'd make it right. They want your vote, but they don't want you to know their plan." Standard "who would have guessed, we disagree with the other party" fare.

Obama said something similar this year, but he wasn't willing to lump Trump in with the rest of the GOP. He understands how to battle with Republicans, even in an age of outsize polarization. Trump is different. "Look," Obama said on Wednesday, "we Democrats have always had plenty of differences with the Republican Party, and there’s nothing wrong with that. It’s precisely this contest of ideas that pushes our country forward. But what we heard in Cleveland last week wasn’t particularly Republican — and it sure wasn’t conservative. What we heard was a deeply pessimistic vision of a country where we turn against each other and turn away from the rest of the world. There were no serious solutions to pressing problems — just the fanning of resentment, and blame, and anger, and hate."

In the end, that last point seemed to be the one that Obama thought would be the most effective against Trump, relying not on the character assassination that has dominated appraisals of the amateur politician and expert attention vacuum — including the president's — but instead disputing his idea of America by pulling hope and change out of storage. On Wednesday night, he even bedazzled it with some Reagan-era USA! quotables: "Ronald Reagan called America 'a shining city on a hill,'" he said at one point. "Donald Trump calls it 'a divided crime scene' that only he can fix."

While everyone who thinks Trump would be a disastrous president tries to figure out how to get past making fun of him and then determine how to dismantle the effect that the candidate has on voters, much of the Republican nominee's campaign feels like it is taking place in an alternate universe. There, Trump is the one mocking everyone else from the White House Correspondents' Dinner stage with carefully chosen and entirely insulting nicknames and self-described sarcasm. His audience are those who have spent the years unconvinced of Obama's "credentials and breadth of experience," who have seen what change Obama has brought to the White House and don't understand how it could have ever happened.

It's a world where no one laughs when Trump says he is going to bring change to the White House. In fact, that's the whole point. As he said in his speech at the Republican convention last week, "Hillary Clinton’s message is that things will never change. My message is that things have to change – and they have to change right now. Every day I wake up determined to deliver for the people I have met all across this nation that have been neglected, ignored, and abandoned."

Regardless of where the election goes next, Trump got at least one win: Five years after Obama's jokes at his expense, America's leaders are taking Trump's brand of change seriously. Obama might hope that a "homegrown demagogue" won't succeed, but we're still in a world where you have to explain why that failure would be a good thing.