On various occasions, both Clintons have indicated it was a mistake and should be corrected.

The Republican Party Platform also calls for reducing incarceration, but the language is not as aggressive as the Democrats'.

The broken US criminal justice and prison system is also featured in Michael Moore's documentary Where to Invade Next?, which features stark comparison with Sweden's system.

Jennifer Smith, from New Bedford, Massachusetts, complained about the racial problem in the US prison system — more African Americans were locked up there than white people.

"If you look at the sheer number of people that were killed by law enforcement, it's two and half times for the African-American community," she said.

Smith, a Sanders supporter, said she is a big believer in community policing. "Police need to be in the community and need to know who the people are and why they are in the neighborhood," she said.

She said only Sanders can fix it and blamed Clinton for "flip-flopping" and not being "consistent like Bernie Sanders".

Asked if Trump would fix the system, she said, "No way."

Protesting in a square across the street from City Hall in Philadelphia, Nicholas Lash of Las Vegas held a poster calling for an end to mass incarceration. He cited the problem of more than 2 million people in the US prisons, the long sentences, having 5 percent of the world's population but 25 percent of world's prisoners — information almost precisely echoing the Eastern State Penitentiary museum exhibit.

Lash also cited the $80 billion the US spends on prison each year, which is roughly $40,000 for each prisoner.

If that money was spent on measures to prevent people from going to prison, the prison population would decline dramatically, he said.

Lash said Sanders and Green Party leader Jill Stein would change the system and complained that Hillary Clinton has lobbyists from the private prison industry working for her campaign, so she is unlikely to change the status quo.

"I will never vote for Hillary. I just can't, I have a conscience," he said.

Linda Boucher toured the penitentiary museum on Monday afternoon. She said maybe simple and petty crimes should be dealt with in ways different from more dangerous crimes like murder and robbery.

Asked if any of the 2016 presidential candidates would fix the problem, she said, "I don't think so, not right away."

"I think it's something they have on the agenda, but I certainly don't have the impression it's high on the agenda," Boucher said.

Contact the writer at chenweihua@chinadailyusa.com