United States President Barack Obama hit the campaign trail for Mrs Hillary Clinton on Tuesday, urging his core voter base - minorities and millennials - which put him in office to support the woman who would continue his legacy.
It was Mr Obama's first solo appearance for the Clinton presidential election campaign, as he hoped to capitalise on his high job approval ratings while Mrs Clinton remained sidelined by pneumonia.
Speaking at a rally in Philadelphia city, Mr Obama decried the way the election was being treated like a reality TV show, and blasted Republican nominee Donald Trump for everything from his promise to be the voice of the working class to his praise for Russian President Vladimir Putin.
"We cannot afford, suddenly, to treat this like a reality show," said Mr Obama.
The President had gone on the stump as Mrs Clinton continued to rest in her home in Chappaqua, New York, after she nearly collapsed during a Sept 11 memorial ceremony in New York on Sunday.
Her spokesman Nick Merrill said she spent Tuesday catching up on briefings, making calls and watching Mr Obama on TV. She is scheduled to return to the campaign trail and speak in Greensboro, North Carolina, today.
Mr Obama urged young people in the crowd to look beyond what was "shiny and new". "You maybe don't remember all the work that she has had to do, and all the things that she has had to overcome. You can't stay home because, 'you know, she's been around for a long time'," he said. "I need you to work as hard for Hillary as you did for me."
Pointing out the irony of Mr Trump's claims that he will be the voice of the working class, he said: "This is a guy who spent 70 years on this earth showing no concern for working people. He spent most of this life trying to stay far away from working people. He wasn't going to let you on his golf course."
Also touching on Mr Trump's apparent admiration for Mr Putin, Mr Obama warned: "Their nominee is out there praising a guy, saying he's a strong leader because he invades smaller countries, jails his opponents, controls the press and drives his economy into a long recession."
"Think about the fact that that is Donald Trump's role model," added the President, who has endured a testy relationship with Mr Putin.
Earlier in the day, Mr Trump's campaign issued a statement with the heading: "Shouldn't you be at work?" targeting Mr Obama's decision to campaign for Mr Clinton instead of solving "major problems facing the country".
Later at a rally in Des Moines, Iowa, Mr Trump took aim at Mr Obama again, saying he would reverse the policies of the past eight years, and "create a future of prosperity for all Americans".
Capitalising on Mrs Clinton's absence, he slammed her for labelling half his supporters as "a basket of deplorables", a comment she had made last week. Mrs Clinton had issued a statement over the weekend saying she regretted using the word "half" but persisted with the view that his campaign was built on "prejudice and paranoia".
Mr Trump said: "While my opponent slanders you as deplorable and irredeemable, I call you hardworking American patriots who love your country and want a better future for all our people."
The Clinton campaign rebutted on Twitter: "Trump and Pence's courting of white supremacists isn't a game: It's normalising racism. And it's deplorable." Mr Mike Pence is Mr Trump's running mate.