Matt Waldrip, executive director of the E2 Summit, said the gathering fosters willingness among people of different backgrounds to work together, even Romney and Biden.
"We saw a real earnest desire from those people who are here, who have tremendous influence in their own circles, to move forward to better our societies … and work with our politicians, whomever they may be, to make things better," Waldrip said.
"I think the sentiment coming out of that [summit] was, 'We're all people trying to do good and are all people trying to influence things for the better, no matter what perspective we come from,' " he said.
Waldrip added, "I know that sounds kumbaya-ish, but frankly it felt kumbaya-ish the last two days."
Biden also told the room full of Republicans that he has just one regret: "That I'm not going to be the president who will preside over the end of cancer," according to a tweet from the E2 Summit's official Twitter account.
The media were not allowed into most sessions at the private summit, so much of the news that came out did so by Twitter, perhaps mirroring how President Donald Trump has handled many of his pronouncements.
On Twitter, a photo showed Romney interviewing Biden on stage Friday night, discussing topics that it said included the "cancer moonshot" an effort launched by Obama and overseen by Biden to eliminate cancer family, and strengthening the middle class.
Biden asked the crowd to raise their hands "if you or someone you know has been diagnosed w/ cancer," according to a tweet. It said every hand went up. Biden said, "So, you get it."
The former vice president, 74, last month unveiled a political action committee that stoked fresh speculation he may seek the presidency in 2020. The committee, named American Possibilities PAC, allows him to raise money for candidates, pay for politically related travel costs and maintain relationships with donors.
In an email to supporters about that PAC, Biden said "the negativity, the pettiness, the small-mindedness of our politics drives me crazy." He did not mention President Donald Trump by name but said that kind of politics is "not who we are."
Biden had considered running for president last year, but said then that continuing grief over the death of his eldest son had "closed the window" on that possibility.
Biden is not the first Democrat to appear at the annual invitation-only Experts and Enthusiasts Summit at Stein Eriksen Lodge. For example, David Axelrod, chief strategist for Obama's presidential campaigns also has been a guest.
Among the top Republicans who spoke to the summit was House Speaker Paul Ryan who was Romney's running mate for vice president in 2012.
"House Republicans are fulfilling our promise to rescue the American healthcare system," he said according to a tweet by the summit. He added, "House Republicans are rebuilding and strengthening our military."
Dean Kamen, the engineer, businessman and inventor of the Segway transport, told the summit, "I tell kids the only difference between science and science fiction is timing," again according to an E2 tweet.
He added, "Every problem represents an opportunity. I am surrounded by endless opportunities."
Stephen Harper, the former prime minister of Canada, made an interesting observation about Russian President Vladimir Putin. "He is a bully, so you must show strength. If Putin senses that someone will punch back, he will back down," an E2 tweet said.
Gerald Chertavian, founder of the Year Up training program for urban youth, told the summit, "Our education and training systems are out of touch with employers' needs and out of reach for young adults," an E2 tweet said.
Another tweet said that he added, "We can/must reimagine talent marketplace: 1) Lead w employer demand. 2) Pay 4 success, not efforts. 3) More pathways; fewer barriers."
Saturday meetings included a panel discussion on politics with Anthony Scaramucci, senior adviser to Trump; Rep. Jason Chaffetz, R-Utah; New Hampshire Gov. Chris Sununu; GOP pollster Kirsten Soltis Anderson; and former American Conservative Union Chairman Al Cardenas, according to an E2 Summit tweet and photo.
Waldrip said Romney is among the few who could gather such people. "He has an ability to convene people to talk about the most important things. Everyone who comes here comes because Gov. Romney asked them to come, and they trust that there will be respectful conversation on important things."
He added, "There was nothing disrespectful that happened here the whole time, and that's what we need."