Inside the sports arena, college students were chanting and doing the wave. The loudspeakers played Sheryl Crow's 2012 song Woman in the White House. A parade of Democratic officials from all levels of government urged the audience to vote: "Run like hell to the polls," said one.

Then two women – Hillary Clinton and Michelle Obama – took to the stage and 11,000 people exploded into cheers. In this long campaign, here was a novel sight: two first ladies of the United States, one former and one current, one white and one black, one with a strong chance of becoming the next president and the other acting as her most powerful champion.

Ms. Obama praised Ms. Clinton's depth of experience, her composure in the face of extraordinary pressure, her skilled campaign. Then, Ms. Obama turned stern.

Story continues below advertisement

"Hillary has done her job, now we need to do our job," she told the crowd. "Because here's where I want to get real: If Hillary doesn't win this election, that will be on us." Ms. Clinton, sitting just to her left, nodded and smiled.

Only 10 days remain until Americans choose their next president. Millions of people have already voted in early balloting across the country. The polls indicate that Ms. Clinton, the Democratic nominee, has a solid – and seemingly firm – lead over Donald Trump, her Republican opponent.

But in North Carolina, the battle is being fought into the last hours. Tim Kaine, Ms. Clinton's vice-presidential candidate, has dubbed it the "checkmate state." Without a victory here, Mr. Trump has no path to victory. And it promises to be close: the only time a Democrat has won North Carolina in nearly 40 years was in 2008, when Barack Obama prevailed with a razor-thin margin of 14,000 votes.

Two days on the campaign trail in North Carolina with both candidates revealed a stark contrast as the race draws to a close. Among Ms. Clinton's supporters, there is the growing realization that something historic may be at hand. Ms. Clinton's long march toward the nation's highest office – from lawyer to first lady to U.S. senator to failed presidential candidate to Secretary of State – is almost complete. If she is victorious, her election could also deliver control of the U.S. Senate to Democrats. At her rally Thursday in Winston-Salem, the crowd was optimistic, young and diverse.

A day earlier, outside the town of Kinston in eastern North Carolina, Mr. Trump attracted a mass of enthusiastic followers, but the mood was embattled. For their candidate to win, everyone has to be wrong about the election – the media, the pollsters, the pundits. His supporters spoke of rigged polls, voter fraud and their belief that Mr. Trump will pull off a shock victory.

For Mr. Trump, the remaining days had presented a conundrum. There were no big moments left on the campaign calendar. But on Friday, it emerged that the U.S. Federal Bureau of Investigation is reviewing new materials in its probe into Ms. Clinton's use of a private e-mail server, a development with the potential to improve Mr. Trump's prospects as the GOP pounced on the news. Ms. Clinton's campaign called on the FBI to immediately provide details of the e-mails being investigated and noted the agency itself is unclear whether they are significant.

One of Mr. Trump's strategies in the waning portion of the campaign, Bloomberg recently reported, is to depress turnout among Democratic voters, including African-Americans. Such a tactic, if successful, could mean the difference between victory and defeat in a place like North Carolina. Here in this swing state, "It is a coin-toss election," said J. Michael Bitzer, a political scientist at Catawba College in Salisbury, N.C. "Not just at the presidential level but at the U.S. Senate and gubernatorial levels."

Story continues below advertisement

Once a Republican stronghold, North Carolina has moved into the swing-state column thanks to the same demographic trends that are reshaping the U.S. electorate to the detriment of the GOP. The state's voters are increasingly urban and younger and it has a growing population of Latino residents.

The election here may be decided well before Nov. 8. Prof. Bitzer said that 65 per cent of the state's voters could cast their ballots through early voting channels. "People are just sick and tired of this election," he said. "They're not waiting, they're showing up."

At Ms. Clinton's rally on the campus of Wake Forest University in Winston-Salem, Democrats from every level of government hammered home a single message: Vote. Alma Adams, a member of the U.S. House of Representatives, deployed two terms used by Mr. Trump during the final presidential debate: "I call on all the 'nasty women' and all the 'bad hombres' to join us at the ballot box," she said.

Ms. Clinton delivered a version of her standard speech on what's at stake in this presidential contest. "I wish I didn't have to say this," she stated in a low voice. "But indeed, dignity and respect for women and girls is also on the ballot. And I want to thank our first lady for her eloquent, powerful defence of that basic value."

Olivia Andreini, 18, a student at Wake Forest University who expects to major in politics, said she would cast her ballot for the first time the following day. "For the first woman president!" she exulted. Ms. Andreini has attended numerous rallies this campaign, but the event with Ms. Clinton and Ms. Obama was the only one that brought her to tears.

"I really felt very close to what they were saying," she said. "I am a female and I am getting an education and because of their work, I can do anything. It's the first time I've internalized that message from a politician."

Story continues below advertisement

Allison Fenderson, 51, drove two hours from her home in the predominantly Republican area of Fuquay-Varina to hear Ms. Clinton and Ms. Obama speak. She believes that Mr. Trump's campaign has galvanized Democratic voters in her area to get to the polls. When she voted early last week, she saw a Hispanic man and his elderly mother register to vote for the first time. "I thought, 'Thank you, Trump, thank you!'" recalled Ms. Fenderson.

Amid the optimism, there were notes of caution. Errol Clauss, 79, said he was concerned about what might happen after Nov. 8. "It's very troubling," he said, as he waited with four members of his family outside Ms. Clinton's rally. "We haven't had an election like this since 1860," he said. "I worry that some of Trump's followers could become angry and violent."

The day before, Mr. Trump touched down in dramatic fashion at an airfield outside the small town of Kinston in eastern North Carolina, an area still reeling from the flooding caused by Hurricane Matthew. In low-lying areas, huge piles of ruined, waterlogged belongings sat outside homes near fields of tobacco and cotton.

Judging by the media, "Hillary is already packing up and backing the van into the White House," said Donald Johnson, 57, a fervent Trump supporter. "It's a way to depress the vote." If Ms. Clinton wins, he said, "I'll probably sink into a deep pit of despair for a week, but I'll come out of it." Mr. Johnson added that he might go into more of a "survivor mode" after a Clinton victory: stocking up on food, purchasing additional firearms.

Norma Poudrier, a 64-year-old retiree from nearby Goldsboro, N.C., was attending a political rally for the first time. She doesn't believe any of the women who have accused Mr. Trump of groping them. "Why are we not hearing more about Bill Clinton's affairs?" she asked. Ms. Clinton, meanwhile, "needs to be in jail."

Mr. Trump's supporters prefer the evidence of their own eyes – the devoted crowds they join at his rallies – to the results of voter surveys conducted by unseen professionals. "Who are they polling?" asked Susan Smith, 39, who lives in Kinston. "We're never polled."

Story continues below advertisement

Just before Mr. Trump's arrival, a pastor from the local New Testament Baptist Church offered a prayer. "Lord, we ask you for Donald Trump and we ask you to spare us" from a potential President Hillary Clinton, he said. As Mr. Trump's plane pulled up to a fenced-in area of tarmac, the main anthem from the film Air Force One rolled over the crowd of a few thousand people.

Mr. Trump, like Ms. Clinton, sounded a bit hoarse from the rigors of the campaign trail. "We're going to win North Carolina and win back the presidency," he promised. "Nobody has ever gotten away with crimes – and I mean crimes – like Hillary Clinton has gotten away with."

He seemed incensed by criticism of his views on the attack on Mosul and by questions about his detour earlier in the day to attend a ribbon-cutting ceremony at the new Trump International Hotel in Washington, D.C. He said the stop was a way to show support for his children's work. "I never practically go home," he protested. Ms. Clinton "wants to sleep all the time. She's a very low-energy person."

After he finished his speech, Mr. Trump briefly shook hands with supporters and climbed the staircase to his waiting plane. He waved, shook one victorious fist, then the door closed behind him. Minutes later, the jet disappeared into the cold October night.

The crowd quickly dispersed. As chairs were folded and the Teleprompter dismantled, Michelle Nix, the vice-chair of the North Carolina Republican Party, predicted a landslide on Nov. 8. "I don't believe the polls at all," she said. "Because everyone I talk to supports Donald Trump."