President Barack Obama on Wednesday night told Americans they face a stark choice in November ― an unusual election that has raised “fundamental” questions “about who we are as a people,” and pitted one of the most qualified candidates in history, Hillary Clinton, against an untrustworthy con man, Donald Trump.

In a Democratic National Convention speech that was at turns emotional and blistering and ended with Clinton appearing by his side, Obama began with a recitation of his accomplishments in office ― reducing unemployment and saving the auto industry, passing health care reform, a nuclear agreement with Iran and the killing of Osama bin Laden.

He acknowledged problems that the country still faces ― people struggling with bills, an epidemic of gun violence ― but he also professed his strong belief in the country’s ability to fix its problems, even if “change is never easy, and never quick.”

Alex Wong/Getty Images President Barack Obama made his case for Hillary Clinton for president Wednesday night.

“The America I know is full of courage and optimism and ingenuity,” Obama said, contrasting this vision with the dark, pessimistic message that came from the Republican convention in Cleveland last week.

“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,” Obama said. “There were no serious solutions to pressing problems ― just the fanning of resentment and blame and anger and hate.”

After laying out those two visions, Obama made his case for Clinton, reminding people not only of her experience and expertise but also of her record of championing groups such as children and veterans.

Obama made a particularly big deal about Clinton’s commitment to public service, in an apparent attempt to turn one of her biggest political liabilities ― her experience in politics ― into an asset. “She knows she’s made mistakes, just like I have; just like we all do. That’s what happens when we try.”

Obama likened Clinton’s grit and determination to Theodore Roosevelt’s. “Hillary Clinton is that woman in the arena. She’s been there for us ― even if we haven’t always noticed.”

And then it was time to talk about Trump. Previous speakers ― including Vice President Joe Biden and vice presidential nominee Tim Kaine ― had already worked up the crowd. Obama picked up where they left off ― at first, by adopting the same mocking tone he’d used in 2011 at the White House Correspondents Dinner.

Mike Segar/Reuters Obama questioned the ability of GOP presidential nominee Donald Trump to protect Americans.

“He’s not really a plans guy,” Obama said of the real estate mogul turned Republican nominee. “Not really a facts guy, either. He calls himself a business guy, which is true, but I have to say, I know plenty of businessmen and women who’ve achieved success without leaving a trail of lawsuits and unpaid workers and people feeling like they got cheated.”

But Obama quickly turned serious, mentioning Trump’s record in business as proof that he would not protect the economic interests of everyday Americans. “Does anyone really believe,” Obama said, “that a guy who’s spent his 70 years on this earth showing no regard for working people is suddenly going to be your champion? Your voice?”

He also questioned Trump’s ability to protect Americans from foreign threats: “He cozies up to Putin, praises Saddam Hussein, and tells the NATO allies that stood by our side after 9/11 that they have to pay up if they want our protection. Well, America’s promises do not come with a price tag. We meet our commitments.”

At one point, Obama invoked an iconic figure from Republican Party history to press his case. “Ronald Reagan,” Obama explained, “called America ‘a shining city on a hill.’ Donald Trump calls it ‘a divided crime scene’ that only he can fix. ... He’s just offering slogans, and he’s offering fear. He’s betting that if he scares enough people, he might score just enough votes to win this election.”

“That is another bet that Donald Trump will lose,” Obama continued. “Because he’s selling the American people short. We are not a fragile or frightful people. Our power doesn’t come from some self-declared savior promising that he alone can restore order. We don’t look to be ruled.”

But the strongest part of his speech came at the end ― when, after painting Trump as somebody who doesn’t believe in America, Obama reasserted his own belief that democracy can work and that, given the chance, they will make the right choices for the country.

“That’s America,” Obama said. “Those bonds of affection; that common creed. We don’t fear the future; we shape it, embrace it, as one people, stronger together than we are on our own.”

Obama’s speech brought the partisan crowd to its feet ― and the roars grew louder when Clinton made her dramatic, if predictable, entrance onstage to join him. The two exchanged words, embraced and then stood on the stage soaking in the applause as the convention’s third night drew to a close.

Robyn Beck/AFP via Getty Images Clinton joined Obama onstage after his speech Wednesday.