Former Vice President Joe Biden officially kicked off his 2020 presidential campaign last month, but part of his populist message borrows from a theme sparked by Democrat Senator Sherrod Brown of Ohio.

Brown made a splash earlier this year with a national tour to talk about the importance of restoring the “dignity of work” to the American middle and working class.

“‘Dignity of Work’ is far from the latest poll-tested rhetorical flourish. It’s not a rebrand released just in time for Sherrod’s foray into the national spotlight,” wrote a columnist supporting Brown in the Des Moines Register. “He’s been saying it in Ohio for years. It’s who he is.”

“The dignity of work means hard work should pay off for everyone, no matter who you are or what kind of work you do,” he told a crowd in Ohio, citing Martin Luther King Jr.

Brown ultimately decided not to run for president, but it appears that Biden borrowed heavily from the theme after it made an impression.

“I measure economic success not by just the growth of the GDP but whether or not we’re able to restore the dignity to the American worker,” Biden told voters in Iowa.

But instead of citing Brown and King, Biden reaches all the way back to the 18th century to cite philosopher Immanuel Kant to kick off the discussion.

“Now let me say what I mean by what I mean when I say dignity,” Biden explained to voters in Iowa on Wednesday. “You know, the philosopher Kant said, he defined dignity and he said, ‘People should never be treated as a means to an end, but as ends to themselves.’ Today organizational structures treat people as a means to an end to their profits, not to those people, and the process stripping us from our dignity.”

He also carefully cited Kant during an appearance on “The View” after announcing his run for president.

“I think by making the case that we have to restore dignity to work. We have to restore dignity to work, we have to restore the way we treat people,” Biden said, adding that, “Kant had this great quote and I’m paraphrasing but he said, you know, dignity is not treating people like a means to an end, which is going on now, but an end in themselves.”

Joe Biden on reaching working-class voters: "We have to restore dignity to work. We have to restore dignity to the way we treat people…We treat them like they're a means to an end." https://t.co/0ZmgnQfjrn pic.twitter.com/85vAzVe9z7 — The View (@TheView) April 26, 2019

Biden’s citation of Kant to discuss the dignity of work is unfamiliar to reporters who have listened to hundreds of his political speeches throughout his career.

Prior to citing Kant on the trail, the former vice president usually relied on the same stump speech about the importance of the middle class and the working class. Biden’s populism was simpler, reaching back on his background in Scranton, Pennsylvania and the history of his family.

It often kicks off with a quote from his father: “My dad used to have an expression, he’d say, ‘Joey a job is about about a lot more than a paycheck, it’s about your dignity, it’s about respect, it’s about your community.'”

From there, Biden tells the story of his father who was devastated when he found out the bank would not loan him the money to help pay for his son’s college or relates the feeling of the “longest walk” of a parent who lost his job.

Biden is not unfamiliar trying to identify with the struggles of the middle class despite never being gainfully employed in his life and serving in elected office for four decades.

He has a history of talking about the working and middle classes, urging Americans to respect them as the “backbone” of America, who built America, not the elite on Wall Street. Labor unions, he insists, are the ones that “brung him to the dance” in politics and vows he will not forget them.

But Biden appears to be borrowing from Brown’s message to sharpen his populist edge.

Part of Brown’s message is that American companies are trading the success of the American worker for the wealth of the stockholders.

“[C]ompanies used to operate in terms of stakeholders: customers, employees and community and shareholders. Now it’s evolved in all that matters is the bottom line,” Brown said. “Many companies operate under the premise that they have to operate only in the stockholder’s best interest. They always use the word fiduciary duty or responsibility. I just don’t think that’s true.”

Biden’s campaign kick-off speech echoed Brown’s.

“CEOs and this administration see it a different way. They see work resistant means to an end, not the end of themselves and themselves,” he said in Pittsburgh. “Look at the record. They treat their employees in a way that – it’s only about how can they maximize the profit? Not how can they maximize the circumstance for the employees and help them build the operation? They’re squeezing the life out of workers.”

Brown’s message also features the inclusiveness of a national campaign focused on the dignity of work, “regardless of your race, regardless of your gender.”

“It’s all workers and all races and both genders,” Brown said in his interview with the Prospect.

Biden is using a similar message on the campaign trail.

“We have to bring everybody along,” Biden told voters in Iowa on Wednesday, “Regardless of race, gender, ethnicity, religion, who they love, where they live, whether they have disabilities, everybody has to be brought along, there’s no reason why it can’t. Everybody!”

Brown recognizes that Biden is borrowing his message on the campaign trail, but does not appear upset about candidates imitating his appeal to the working class.

“When we set out on our Dignity of Work Tour, we went to four states and talked about the dignity of work,” he told the American Prospect in an interview. “Joe Biden used that term a number of times.”

Brown added that Sen. Kamala Harris and Sen. Elizabeth Warren also started speaking about “the dignity of work” on the 2020 campaign trail.

“This is becoming a Democratic theme,” he said. “That means respecting work—whether you punch a clock or swipe a badge, whether you’re working on a salary or working for tips, whether you’re taking care of an aging parent or raising children yourself.”

It’s unclear why Biden is citing Kant as the inspiration of his treatise on the dignity of work. It does not slip off the tongue and Biden usually apologizes to the audience for quoting a philosopher at a retail campaign stop.

“It’s a strange thing to be quoting Kant at a political event,” he admitted to voters in Iowa on Wednesday.

The concept of the dignity of work is not foreign to presidential election campaigns either as the United States has a rich history of promoting the free and prosperous American worker. Catholic social teaching also emphasized the dignity of work in response to the rise of socialism in the 20th century, when Biden was going to school. Biden is not unfamiliar with Kant either. He cited Kant in his 2017 book about the loss of his son Beau to cancer. He also cited Kant about grief in an appearance on “The View” with Megan McCain in 2017.

But in March, Brown also welcomed the idea of other candidates using his message.

“The more they mention it, the better it is. I’m glad they’re mentioning it,” Brown told Vox. “We knew that if I didn’t run, it’d still have an impact on the debate.”