For the first time since 2008, President Barack Obama and presumptive Democratic presidential nominee Hillary Clinton campaigned together in Charlotte, N.C. Tuesday afternoon. Only this time it was Obama stumping for Clinton.

Clinton was first up at the rally in a critical swing state, and after praising the president and noting their productive relationship, particularly when she served as his secretary of state, she launched her first of several digs at the GOP nominee, Donald Trump.

“And Donald, if you are out there tweeting, it is Hawaii,” she said, clearly mocking Trump’s charge that Obama wasn’t born in the U.S. She said as her relationship evolved from political rivals, to partners, to friends, “My esteem for him kept growing.”

She set the tone for their mutual admiration society speeches, and because it’s her race, Obama had the longest time at the dais with expressions of love and support that each time was interrupted by resounding applause and chants of “Hillary! Hillary!”

“We may have gone toe to toe, coast to coast,” Obama said, recalling their furious exchanges in 2008, “but we stood shoulder to shoulder for the ideals we shared.”

Obama said his faith in Clinton has always been rewarded. “I have had a front row seat to her judgment, to her toughness and her commitment to diplomacy,” he said, “and I witnessed it in the Situation Room when she argued in favor of getting [Osama] Bin Laden.”

The president repeated some of the accolades he cited when he first endorsed Clinton, noting that there has never been “a person more qualified to be our commander-in-chief.”

Behind them was a cheering crowd, mostly African-American, and a banner emblazoned with the words “Stronger Together.” And if they can keep this kind of energy going for the next few weeks as the convention approaches in Philadelphia, it should help Clinton capture some of the disgruntled supporters of Sen. Bernie Sanders, who, by the way, was not mentioned.

And neither of them gave any real attention to the decision by the FBI not to bring charges against Clinton about her email server, although he did chide her indiscretions and mishandling, which should be fodder for Trump, who was scheduled to speak later Tuesday.

It was a rousing beginning for Clinton and Obama, and it’s pretty predicable they will focus their duets on the swing states, hoping to improve Clinton’s poll numbers that slipped to a single digit lead over Trump.

The Charlotte moment gives the campaign a needed boost and prepares the two Democrats for the sessions at the convention, and it will be hard to match the enthusiasm and bonhomie expressed Tuesday.

Obama made his 2016 campaign debut with Clinton just hours after FBI Director James Comey slammed the Democratic presumptive nominee’s email practices in brutal terms.

Appearing onstage with Clinton in Charlotte after lending her a ride from Washington on Air Force One, Obama sought to confer his popularity on a candidate still struggling to gain voters’ trust. He touted the four years she served as his top diplomat as evidence of tough-nosed grit, and acknowledged that he himself is a Clinton convert after their nasty 2008 primary campaign.

“I came away from that primary admiring her even more because during that year-and-a-half, I had a chance to see up close, just how smart she was and just how prepared she was, especially since I debated her a couple dozen times,” Obama said. “I saw how even when things didn’t go her way, she’d just stand up straighter and come back stronger.”

Clinton, too, discussed their hard-fought race from eight years ago.

“I feel very privileged because I’ve known the president in many roles,” Clinton said, speaking next her one-time boss. “As a colleague in the Senate, as an opponent in a hard-fought primary, and the president I was so proud to serve as secretary of state. I also know him as the friend that I was honored to stand with in the good times and the hard times. Someone who has never forgotten where he came from.”

But what should have otherwise been a celebratory moment for Clinton was partly overshadowed—yet again—by a scandal that continues to dog her campaign. Comey announced Tuesday morning just hours before the Clinton-Obama joint appearance that the former secretary of state’s use of a private email server during her tenure at the State Department was “extremely careless.”

Although Comey said that he would not recommend charges against Clinton, the long-awaited announcement, coming after Clinton’s lengthy interview at the FBI headquarters over the weekend, was a striking rebuke of the Democratic Party’s presumptive White House nominee. Even with the federal probe wrapping up, Republicans continue to seize on the email controversy as Clinton seeks to shed the perception that she is untrustworthy and dishonest.

“Although we did not find clear evidence that Secretary Clinton or her colleagues intended to violate laws governing the handling of classified information,” Comey said, “there is evidence that they were extremely careless in their handling of very sensitive, highly classified information.”

With polls suggesting that more Democrats trust Obama than Clinton, the president will no doubt be one of Clinton’s most powerful surrogates in the general election.

Starting with Obama’s first in-person call for Clinton’s election Tuesday, Clinton aides hope the second-term president will serve as a validating voice that can vouch for Clinton’s character, fitness and qualifications. The president, Democrats believe, can rouse voters not yet clamoring for Clinton.

Obama’s push for Clinton comes after months of waiting. Like most Democrats, he expected his party’s primary to conclude far sooner than it did. The Orlando terrorist shooting last month further postponed Obama’s first campaign event, as the president grew increasingly revved up to appear alongside Clinton, according to aides.

Originally, Obama and Clinton were set to appear in Wisconsin, a state where Sen. Bernie Sanders handily won the Democratic primary. But with Sanders hinting that he’ll soon offer Clinton his full-throated backing, the campaign opted instead for a stop in North Carolina, which Obama lost narrowly in 2012. The pair campaigned only blocks from the site of that year’s Democratic National Convention.

Clinton’s top aides believe North Carolina is the biggest must-win for Trump, and their best chance to flip a state that Mitt Romney won in 2012. Clinton first deployed general election staff to North Carolina in late April and their first ads in the state began running in June.

Underscoring the importance both sides are placing on North Carolina, Trump also campaigned in the state Tuesday, appearing after Clinton during an evening event in Raleigh.

The Clinton campaign and the White House also believe Obama can help galvanize the state’s large African-American population to vote in November. Defeating Trump will require turning out the coalition of young people, suburban women and minorities that helped Obama win two presidential elections.

Soon joining Obama on the trail is Vice President Joe Biden, who plans to stump for Clinton in his hometown of Scranton, Pa., later this week.

For the president, a Trump presidency has become a nightmare scenario that has the potential to undo much of the work he’s focused on over the past seven years. As recently as last week, Obama was issuing executive orders in the hopes of institutionalizing the priorities of his administration.

In what’s becoming a regular occurrence, Obama used a foreign press conference (in this case, in Canada) to denounce Trump as the antithesis of populism. It wasn’t the first time Obama ripped into Trump abroad. Less than a month after the billionaire announced his candidacy, Obama shamed Trump for his criticism of Sen. John McCain during a news conference in Ethiopia.

“He’s a force multiplier for her,” said David Axelrod, Obama’s former senior adviser who now serves as a senior CNN political commentator. “When you think about it, Donald Trump is really the star of his show, and the supporting cast. She will have people out there and the president, chief among them, who can really bring the case.