PHILADELPHIA -- Hillary Clinton had an iPhone in her hand when she stepped out of her black “Scooby” van onto the tarmac at the airport in White Plains, New York on Monday morning. She was about to board her campaign plane for her last day on the campaign trail, and she was FaceTiming with her granddaughter, Charlotte.

“Bye, honey, I love you,” Clinton said. She told reporters waiting for her under the plane’s wing that she wanted to show Charlotte the “big plane” and the “big press.”

It seemed like fitting start to the day, which would take the Democratic nominee to four different cities in three different states and then back home to New York, where she’ll cast her vote in the presidential election on Tuesday. They’ve never appeared with her, but Clinton’s grandchildren have always had a presence on the road, even during the final stretch.

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“When your kids and your grandkids ask you in the future what you did in 2016, when everything was on the line,” Clinton said at a rally in Pittsburgh a couple of hours later, “you’ll be able to say you voted for a stronger, fairer, better America where we build bridges, not walls.”

She made few direct references to her opponent, Donald Trump, choosing instead to emphasize the choice facing voters headed to the polls. It’s a choice, she said, between “division and unity” and between “strong and steady leadership and a loose cannon.”

Clinton strayed from her prepared remarks when she saw Mark Kramer, a 66-year-old coal worker in the crowd. He held a sign that read “Coal Miners for Hillary.”

“I’ll tell you, sir,” she said, speaking directly to Kramer. “I know how hard times are and as I have said, and you can take it to the bank, I will not forget you...We are not going to forget any American.”

She implored the crowd: “If the lines are long tomorrow, please wait.”

Later, at a rally near Grand Rapids, Clinton took a harder line against her opponent on the economy. Her campaign has acknowledged that the race in Michigan, traditionally a blue state, has “tightened” in recent weeks and moved quickly over the weekend to defend it.

“He’s gone all over Michigan, talking about how he’s going to really get more jobs and he’s going to bring back what used to be there,” Clinton said about Trump. “Well, I’ll tell you what, look at his record. Don’t just listen to this rhetoric.”

She joked that “one of the mysteries in this campaign” will be how Trump lost nearly a billion dollars in a year, as shown on a portion of his tax return from 1995 uncovered by the New York Times.

“He’s not going to release his tax returns between now and the time you start voting,” she said. “And that sort of suggests there must be coming really terrible in those tax returns.”

Even later Monday, in front of a crowd of tens of thousands at Independence Hall in Philadelphia, Clinton said she “deeply” regrets “how angry the tone of the campaign became” over the last 18 months.

“It’s not your fault!” came a voice from the crowd.

Clinton spoke briefly -- sixteen minutes, after performances by Jon Bon Jovi and Bruce Springsteen, and speeches from her husband and the President and First Lady -- and said that Americans’ core values are being tested in this election.”

“We know who he is,” Clinton said. “The real question for us, is what kind of country we want to be? And what kind of future we want to build for our children.”

From Philadelphia, Clinton traveled to Raleigh, North Carolina -- with Jon Bon Jovi hitching a ride with her -- for a midnight rally with her husband and daughter, Chelsea, where Lady Gaga performed. An aide explained that, while Clinton’s rally with the president and first lady was a finale of sorts for her, it was the candidate who wanted to squeeze in one more stop.

“It is such an amazing combination of emotions,” Clinton told Ryan Seacrest in a radio interview. “Because it is physically demanding, obviously. You’ve got to cap this endurance test to run for President. But it’s also exhilarating, and it’s so energizing and exciting.”

She said she would get two, maybe three, hours of sleep on Monday night.

“I don’t think there’ll be a lot of sleep to be found,” she said.