obama
U.S. President Barack Obama pauses as he speaks during a campaign event in support of U.S. Democratic presidential candidate Hillary Clinton in Philadelphia, Sept. 13, 2016. Carlos Barria/Reuters

With Hillary Clinton sidelined by pneumonia, President Barack Obama took up the Democrats' fight against Donald Trump on Tuesday, trying to quash the Republican presidential candidate's bid to appeal to working-class voters.

Obama, whose 50 percent job approval rating could help improve the climate for the Democratic ticket in the Nov. 8 election, rallied party faithful against Trump, the 70-year-old New York real estate developer, at an outdoor event in Philadelphia.

"This is a guy who spent 70 years on this earth showing no concern for working people. He spent most of his life trying to stay far away from working people. He wasn't going to let you on his golf course," Obama said.

Obama's campaign appearance was his first as a solo act on behalf of Clinton as he tries to ensure Democrats retain control of the White House once his eight years are over in January.

The president lauded new census numbers on income growth as proof that his administration's policies have helped improve the economy, an attempt to undermine Trump's argument that economic woes are deep.

"By so many measures, America is stronger and more prosperous than when we started out on this journey together," Obama said.

Clinton, who was Obama's secretary of state during his first term, rested at her home in the New York City suburb of Chappaqua, as she recovers from pneumonia. She was diagnosed with pneumonia on Friday but she kept it secret until she nearly collapsed on Sunday at a ceremony in Manhattan marking the Sept. 11, 2001, attacks.

She is to return to the campaign trail on Thursday, her spokesman Nick Merrill said Tuesday evening.

Her campaign said in a statement that she will deliver remarks in Greensboro, North Carolina, on Thursday and "discuss her vision for an America that is stronger together."

Trump on Child Care

Trump appeared at a campaign event in suburban Philadelphia after Obama departed, touting proposals that would allow families to deduct child-care expenses from their income taxes and establish paid maternity leave for women whose employers do not offer it. The plan, he said, was aimed to bolster working-class and middle-class families.

With his daughter Ivanka at his side, Trump also appeared to support equal pay for women, traditionally a core issue for Democrats.

"We need working mothers to be fairly compensated for their work and have access to affordable quality child care for their work," Trump said.

As he did earlier in the day at a rally in Des Moines, Trump steered clear of mentioning Clinton's illness but stepped up efforts to wring maximum advantage from her controversial comment that his supporters are “deplorables."

"While my opponent slanders you as deplorable and irredeemable, I call you hardworking American patriots who love your country," said Trump, who has tried to portray the former first lady as out of touch with ordinary Americans.

Clinton said in a speech last week that half of Trump's supporters belong "in a basket of deplorables" and accused them of being racist and homophobic. She later said she regretted the remark.