NC gets double dose of presidential campaign

"She's laughing at the stupidity of our system." he said. "Today's the best evidence that we've ever seen that our system is rigged."

Repeatedly calling her "crooked Hillary," Trump suggested she bribed Attorney General Loretta Lynch by offering to keep her in the post if Clinton wins in November and traded favors in the State Department for donations from individuals and foreign governments to the Clinton Foundation or for speaking fees for herself or her husband, former President Bill Clinton.

"This is one of the most crooked politicians in history," Trump said. "She can't keep her emails safe, and I tell you, folks, she sure as hell can't keep our country safe."

Meanwhile, President Barack Obama lauded Clinton's experience, temperament and policies on Tuesday afternoon, calling her the "most qualified" person to succeed him in the White House.

Making his first appearance on the campaign trail for Clinton during an hour-long rally at the Charlotte Convention Center, Obama acknowledged that Clinton "has her critics" after years in the public eye, but he made no mention of the email scandal. Rather, he told the cheering crowd about his evolving relationship with Clinton – from political rivals to colleagues and friends – and how he was prepared to "pass the baton" to her to move the country forward in the coming years.

"There's never been any man or woman more qualified for the office than Hillary Clinton," Obama said. "Bottom line, I know Hillary can do the job."

Trump also hinted at a conspiracy in the timing of the FBI announcement, noting it conveniently came hours before the president and Clinton would share the stage.

With the president sitting on a stool off to the side, nodding in agreement and applauding, Clinton opened the rally by outlining her goals:

She likewise expressed admiration for Obama's accomplishments over the last eight years, saying the next president needs to build on that record.

"I don't think he gets the credit he deserves for saving our economy," she said. "That is what leadership looks like."

She then swapped placed with Obama, sitting on the stool as the president became campaigner-in-chief for about 45 minutes.

"I have had a front-row seat to her judgment and her toughness and her commitment to diplomacy," he said of their work together during his first four years in office. "I saw how deeply she believes in things she fights for. I saw how you can count on her and how she won't waver. She won't back down, and she will not quit, no matter how difficult the challenge."

Obama never mentioned Trump by name – Clinton's only reference was calling him by his first name in a joke about Trump's penchant for tweeting – but he frequently criticized Trump's policies and bombastic demeanor.

"If your concern is working people, then this is not a choice," Obama said. "If you vote for the other team, it's not because of the economy."

Clinton, he said, has an economic plan that will help millions of Americans improve their lot in life, while Trump offers only "harsh rhetoric" and policies that "help the folks at the top do even better."

Trump, for his part, blasted Obama as "a carnival act," saying he was wasting taxpayers' money by campaigning with Clinton instead of staying in Washington, D.C., to deal with ISIS and the nation's economy.

He said his tax plan would cut income taxes for middle-class families and encourage corporations to bring jobs and profits back to the U.S.

On foreign policy, Obama called Clinton a "stateswoman" who's able to build international coalitions to back U.S. interests, while Trump provides "phony bluster" and treats everyone like the cast and crew of a reality television show.

Trump said he would be a tough negotiator on trade deals and would create such military might that no country would try to challenge the U.S.

"We need someone with a tough temperament. It's time," he said, calling Clinton "a weak, weak person."

"We need fresh, tough, bold ideas," Trump said. "We need people who know what they're doing."

Trump's plan to build a wall along the border with Mexico is always a major applause line at his rallies, but when Obama mentioned it in Charlotte, the crowd booed lustily.

"Don't boo, vote," Obama chided them. "Booing doesn't help. We need you to vote."