PHILADELPHIA - Christine Williams is spending the Democratic convention with her back turned mostly to the stage. She's an usher guarding a nosebleed-section doorway. Yet she made sure to spin around and snap a picture of a once-in-a-lifetime moment Wednesday.
The young woman had never seen Barack Obama speak - she's from his hometown, Chicago, but it took a work stint in Philadelphia to bring her within camera range of the president.
Some people wept as he entered, following a video that chronicled the highs and lows of his presidency: the health law, the Bin Laden raid, relations with Cuba, the economic turnaround, the Iran nuclear deal, and mass shootings that made him weep too.
Some grasped at signs with his name being handed out. One man screamed, "Best president ever!"
The usher took a photo.
"I've been blessed to have this opportunity," Williams said.
"To hear him in person. Capture a picture. It's amazing."
The biggest star in the Democratic party urged its members to chart a course toward Hillary Clinton, in a speech where he acted as a top-level character witness, having gone from her rival, to colleague, to staunch supporter.
Obama called her the most qualified person ever running for president; said she'd shown her lifelong commitment to social causes; and compared her to an opponent who had never shown any regard for ordinary people.
He cast the election as a moral choice - not simply between left and right, or Democrat versus Republican, but as a national referendum on whether the country would abide by its optimistic and pluralist traditions or turn to hatred and bitterness.
"The choice isn't even close," Obama said. "People outside the United States don't understand what's going on in this election."
When he mentioned Donald Trump's name, people booed. Obama cut them off: "Don't boo. Vote!... I ask you to do for Hillary Clinton what you did for me." At the end, she joined him onstage prompting a rise in decibel levels from the crowd.
And that's the president's role. In an election where his party is seeking a rare third term, Obama is being deployed as the base-mobilizer-in-chief. His favourable rating is about 10 percentage points higher than Clinton's among the general public, due partly to the affection for him within the party.
The choice of locale for their first joint appearance recently offered clues into how she intends to deploy her campaign ally. They appeared together in North Carolina, a state with a large African-American population that he carried in 2008.
If she can mobilize a similar minority turnout from young African-American voters like Williams, it might blunt gains Republicans are hoping to make among working-class whites in states like Pennsylvania and Ohio. A civil-rights icon urged the party to come together for Clinton.
"If blacks register and vote in great numbers, progressive whites win," Jesse Jackson told the crowd Wednesday.
"Women win. When women win, children win... It's Hillary time."
The obstacle to that has been glaringly evident throughout this convention. The lack of enthusiasm on the far left has translated into protests and sporadic boos from the floor since Monday.
A small minority even jeered during a speech from former New York mayor Michael Bloomberg - who came to ridicule the business track record of his fellow Manhattan billionaire, Trump, while endorsing Clinton.
Speakers and videos throughout the evening mentioned mainstream Republicans - John McCain, Mitt Romney, Marco Rubio, Barbara Bush and John Kasich - in a transparent campaign to swipe some moderate votes.
A lifelong Republican, former admiral John Hutson, referred to Trump insulting the 2008 nominee: "Donald, you're not fit to polish John McCain's boots."
Obama made a similar pitch, to Clinton's detractors on the left and right. People around the arena showered their love on him. They booed when he referred to the end of his presidency. One man shouted, "Four more years!"
Claire Merced campaigned for him in 2008.
When asked who she was most excited to hear speaking at this convention, she mentioned the president. The schoolteacher called him a compelling speaker, kind, and a good representative for the country these last eight years.
A constitutional amendment passed six decades ago precludes him from running again. Merced paused when asked whether she wished he could go for a third term: "I mean, I would love..." she began.
Then she added that she supports term limits and said: "I think it's time for other people, with new ideas. And, if it's Trump," she went on, adding a touch of dark humour, "to destroy the country."
She was wearing a Hillary Clinton button.
Over in the doorway, Williams was of a similar mind. She sounded a bit wistful when asked whether she yearned for a third Obama term: "Kind of. Yes," she said.
"But things are always changing."
