Trump, who had never before run for public office, won on a broad wave of support both from the Republican U.S. heartland and by flipping previously Democratic states, including Pennsylvania, Florida and Ohio, helping his party protect majorities in both chambers of Congress.
The victory stunned residents of major cities up and down the East and West coasts, many of whom had trusted opinion polls that had long predicted a Clinton victory but were proven profoundly wrong by Tuesday's results.
"I'm feeling physical pain. I'm shocked. I'm sad," said Sofia Huizar, 30, as she waited outside the Manhattan hotel where Clinton conceded her loss on Wednesday morning, some eight hours after Trump declared victory.
Huizar, a U.S. citizen who was born in Mexico, said she spent much of Tuesday night commiserating with family across the border. "It's a way to help process the fear," Huizar said.
Trump's campaign promises have included building a wall along the U.S.-Mexico border to stop illegal crossings and to deport the estimated 11 million undocumented immigrants living in the United States.
Others, like Kim Priban, a 38-year-old nurse who lives in the Cleveland suburb of Boston Heights, Ohio, said they had a difficult time breaking the news to their children.
Priban said she had proudly taken her 5-year-old daughter along to vote for Clinton, who would have been the first woman U.S. president, and on Wednesday morning had to discuss the result with her.
"I still haven't quite figured out what to tell my daughter. I've been crying all day," Priban said. "I feel like I have to go out and make my voice heard for women and children."
Priban and Huizar are likely far from alone in the depth of their pain over Clinton's loss, academic research suggests.
A 2015 paper by researchers at Harvard University found that voters who supported Republican Mitt Romney's unsuccessful White House bid reported sharper spikes in their unhappiness than parents following the 2012 Sandy Hook massacre of Connecticut schoolchildren or Boston residents after the deadly 2013 Boston Marathon bombing.
'DISRUPTER, FOR BETTER OR WORSE'
While many Democrats along the coasts mourned Clinton's defeat, Trump supporters celebrated the outcome, saying they hoped he would shake up a dysfunctional political system.
"The overwhelming majority of Americans want change, and this is a direct result. ... Trump is the disrupter, for better or for worse," said Kelley Smith, 33, who lives in Chicago and works in software sales. "He's a little bombastic. I don't think he's polished. But I don't think he’s going to purposefully take our country down."
The divide between the coasts and the heartland, evident not only in the results but also in the social media battles ahead of the election, made the Trump victory more shocking for liberals.
Deena Pioli, an attorney from San Francisco, said she had rarely run into people who were not supporting Clinton, and that she now regrets that.
"Those of us here in San Francisco and California should not be so safe in our bubble," she said.
Trump dropped his angry speaking style to take a conciliatory tone when he declared victory early Wednesday morning, saying, "I pledge to every citizen of our land that I will be president for all Americans."
Clinton and Democratic President Barack Obama sounded similarly restrained. But the breadth of Trump's win left his opponents urging self-examination.
"Folks should have deep humility in this moment," said civil rights activist DeRay Mckesson on Twitter. "We all have things to learn from how Trump happened."
Karen Parnett, a 48-year-old mother of three in Cambridge, Massachusetts, said she had been heartbroken to tell her children about Trump's win, and said the result illustrated the growing anger of lower-income voters who believe their concerns are being ignored by Washington.
"I have too much at stake with three kids to just throw up my hands and weep and say that all is lost," Parnett said. "There are new realities and we need as a country to reckon with what in the world we are going to do about the disenfranchisement of the white working poor."