Obama: I'm ready to pass the baton to Hillary Clinton
US President Barack Obama has heartily vouched for Hillary Clinton's trustworthiness during his first outing on the campaign stump for his former secretary of state just hours after his FBI director blasted her handling of classified material,
Shirt sleeves rolled up in campaign form, Mr Obama told a rally in North Carolina: "I'm ready to pass the baton."
And in a resounding endorsement of Mrs Clinton, he added: "I'm here today because I believe in Hillary Clinton. I have had a front-row seat to her judgment and her commitment."
He spoke at his first joint campaign appearance with Mrs Clinton, a show of Democratic unity in a state Mrs Clinton is hoping to put back in the Democrats' column.
But shortly before the president and his would-be successor flew to Charlotte together, FBI Director James Comey announced he would not recommend charges against Mrs Clinton for her email practices - but only after he presented a searing description of her "extremely careless" handling of classified information that ensured the matter won't be going away.
The White House declined to comment on the findings, saying the investigation was not formally closed and it did not want to appear to be influencing prosecutors.
Still, the timing of the trip pulled the president into a controversy he has at times tried to keep at arm's length.
Yet Mrs Clinton and Mr Obama did not veer from their display of unity. The duo flew to Charlotte together on Air Force One and they rode to the rally together in Mr Obama's armoured limousine.
As they were welcomed by a screaming crowd of supporters, the president led chants of "Hillary!" as they stood onstage under banners reading "Stronger Together".
Referring back to their own primary battle in 2008, Mr Obama said, "We may have gone toe to toe, from coast to coast, but we stood shoulder to shoulder for the ideals that we share."
Mrs Clinton's Republican rival Donal Trump did not let the display go unanswered. As the rally began, he released a lengthy statement casting her joint appearance with Mr Obama as an example of a "rigged" political system.
"It was no accident that charges were not recommended against Hillary the exact same day as President Obama campaigns with her for the first time," Mr Trump said.
Mrs Clinton shot back as she introduced the president, chiding her rival for once questioning the president's birthplace.
She said Mr Obama was a man that "I was honoured to stand with in the good times and the bad times, someone who has never forgotten where he came from. And, Donald, if you're out there tweeting, it's Hawaii."
Mr Obama, too, got in a dig at Mr Trump.
"Anybody can tweet but nobody actually knows what it takes" to be president, he said.
Mr Obama's and Mrs Clinton's journey from political opponents to close political allies was a steady theme in the event.
The Clinton campaign hopes Mr Obama can reassure voters about her experience, talent and character - and speak to their questions about her honesty and trustworthiness, some of which stem from the email investigation.
Recounting his primary debates with Mrs Clinton, he said, "She knew every fact, ever detail. ... Even when things didn't go her way, she just stands up stronger."
Mrs Clinton noted that she has been Mr Obama's loyal ally, serving in his Cabinet when asked and then travelling the world representing his foreign policy.
The pair originally planned to make their first campaign appearance together in Wisconsin, a Democratic-leaning state where Mrs Clinton struggled in her primary fight with Bernie Sanders. Campaign aides viewed that as a way to forge Democratic unity after the bruising primary and consolidate the party's voters in a state she needs to carry in November.
The June 15 rally was postponed due to the mass shooting at an Orlando nightclub. By the time the campaign and White House got around to rescheduling, Clinton aides said the landscape had shifted - they are now far less worried about bringing along Sanders voters and more interested in using the president to rally voters in one of the most divided general election battlegrounds.
Mr Obama narrowly won North Carolina in the 2008 presidential election, becoming the first Democrat to win the state since 1976. But he was dogged by a sluggish economy and disappointment among some swing voters during his 2012 re-election, and lost to Republican Mitt Romney by 2 percentage points.