Peter Dreier is professor of politics at Occidental College and author of " The 100 Greatest Americans of the 20th Century: A Social Justice Hall of Fame " (Nation Books, 2012). The opinions expressed in this commentary are solely those of the author.

(CNN) Now that Sen. Bernie Sanders' presidential campaign is generating lots of media attention, the word "socialism" is in the news. But few Americans know what it is or what Sanders means when he describes himself as a "democratic socialist."

In the early 1900s, socialists led the movements for women's suffrage, child labor laws, consumer protection laws and the progressive income tax. In 1916, Victor Berger, a socialist congressman from Milwaukee, sponsored the first bill to create "old age pensions." The bill didn't get very far, but two decades later, in the midst of the Depression, President Franklin D. Roosevelt persuaded Congress to enact Social Security. Even then, some critics denounced it as un-American. But today, most Americans, even conservatives, believe that Social Security is a good idea. What had once seemed radical has become common sense.

Much of FDR's other New Deal legislation -- the minimum wage, workers' right to form unions and public works programs to create jobs for the unemployed -- was first espoused by American socialists.

Socialists were in the forefront of the civil rights movement from the founding of the NAACP in 1909 through the Voting Rights Act of 1965. Socialists have long pushed for a universal health insurance plan, which helped create the momentum for stepping-stone measures such as Medicare and Medicaid in the 1960s and Obamacare today.

In the 1890s, a socialist Baptist minister, Francis Bellamy, wrote "The Pledge of Allegiance" and a socialist poet, Katherine Lee Bates, penned "America the Beautiful." Throughout our history, some of the nation's most influential activists and thinkers, such as Jane Addams, John Dewey, Helen Keller, W.E.B. DuBois, Albert Einstein, A. Philip Randolph, Walter Reuther, Martin Luther King, Eugene V. Debs, and Gloria Steinem, embraced democratic socialism.

King believed that America needed a "radical redistribution of economic and political power." In October 1964, he called for a "gigantic Marshall Plan" for the poor -- black and white. Two months later, accepting the Nobel Peace Prize in Oslo, he observed that the U.S. could learn much from Scandinavian "democratic socialism." In fact, he told his staff, "There must be a better distribution of wealth, and maybe America must move toward a democratic socialism."

During the Cold War, many Americans confused democratic socialism with communism. In fact, democratic socialists opposed the totalitarian governments of the Soviet Union, China and their satellites. That's because democratic socialism is about democracy -- giving ordinary people a greater voice in both politics and the workplace.

Although Sanders says that America needs a "grassroots political revolution," he is actually a reformer, not a revolutionary. His version of democratic socialism is akin to what most people around the world call "social democracy," which seeks to make capitalism more humane.

This is why Sanders says that the U.S. should learn from Sweden, Norway and Denmark -- countries with greater equality, a higher standard of living for working families, better schools, free universities, less poverty, a cleaner environment, higher voter turnout, stronger unions, universal health insurance, and a much wider safety net

Sounds anti-business? Forbes magazine ranked Denmark as the #1 country for business. The United States ranked #18.

European social democracies put greater emphasis on government enterprise, but even most Americans favor government-run police departments, fire departments, national parks, municipally-owned utilities, local subway systems and public state universities.

Socialists believe in private enterprise but think it should be subject to rules that guarantee businesses act responsibly. Banks shouldn't engage in reckless predatory lending. Energy corporations shouldn't endanger and planet and public health by emitting too much pollution. Companies should be required to guarantee that consumer products (like cars and toys) are safe and that companies pay decent wages and provide safe workplaces.

Sanders' socialism means reducing the political influence of the super rich and big corporations, increasing taxes of the wealthy to help pay for expanded public services like child care, public transit, and higher education, reducing barriers to voting, and strengthening regulations of business to require them to be more socially responsible in terms of their employees, consumers and the environment. That means a higher minimum wage, paid sick days and paid vacations, and safer workplaces.

Because the word "socialism" has been demonized, few Americans call themselves socialists or even social democrats. But public opinion polls -- including the Pew Research Center, Hart Research Associates and The New York Times/CBS -- show that a vast majority of Americans agree with what Sanders actually stands for.

For example, 74% think corporations have too much influence; 73% favor tougher regulation of Wall Street; 60% believe that "our economic system unfairly favors the wealthy;" 85% want an overhaul of our campaign finance system to reduce the influence of money in politics; 58% support breaking up big banks; 79% think the wealthy don't pay their fair share of taxes; 85% favor paid family leave; 80% of Democrats and half the public support single-payer Medicare for all; 75% of Americans (including 53% of Republicans) support an increase in the federal minimum wage to $12.50, while 63% favor a $15 minimum wage; well over 70% support workers' rights to unionize; and 92% want a society with far less income disparity.

On those matters -- both broad principles and specific policy prescriptions -- Sanders is in sync with the vast majority of Americans. There's a great deal of pent-up demand for a candidate who articulates Americans' frustrations with the status quo. That's what American socialists have been doing for over a century. Indeed, socialism is as American as apple pie.