After months of expectation, US senator and presidential candidate Bernie Sanders has at last given what might be remembered as one of the landmark speeches of the 2016 election: an explanation and defence of his position as a “democratic socialist”.

Linking his beliefs to revered figures from US history such as Franklin Roosevelt, Lyndon B. Johnson, and Martin Luther King Jr, he attempted to show that socialism was not just a “route to economic fairness” but also “essential to American values”.

Perhaps most importantly, it provided Sanders with another opportunity to present his socialist ideas to a national audience, something that was once almost unthinkable in modern US politics.

Long demonised in American electoral politics, “socialism" seems to be resonating with many Americans upset by the country’s deepening economic inequality and insecurity – and it has the potential to expand the limits American democracy.

Sanders has surprised the political establishment by becoming a serious nominee for president. Most assumed that a socialist was simply “unelectable”. Even left leaning politicians who share his views, like Democratic congressman Alcee Hastings lament:

No matter how well you think of Bernie – and all of us do … when the politics of it all hits the road, I don’t feel – and I feel most members don’t feel – that he can be elected.

Meanwhile, conservatives warn that his victory would “transform the nation” to be almost completely “controlled” by the government, or dismiss his proposals as a dangerous economic fantasy.

For many on the left, the goal was always to drag near-inevitable nominee Hillary Clinton “to the left”. Their hope was include progressive ideas within mainstream political discourse with the hope of spurring a leftist populist movement. Sanders himself declared that winning matters less than creating a “political revolution” against the “billionaire class”.

#feelthebern

The historic importance of Sanders’s campaign goes beyond winning or losing. He is reviving a long dormant American socialist tradition, updating the legacy of past leftist politicians like Eugene Debs. The real test is whether he can “keep socialism alive” in a political culture that until recently considered these ideals irrelevant.

In this year’s first Democratic debate, when asked directly if a socialist could win the White House, he responded:

Well, we’re gonna win because first, we’re gonna explain what democratic socialism is. And what democratic socialism is about is saying that it is immoral and wrong that the top one-tenth of 1% in this country own almost as much wealth as the bottom 90%.

Despite the media pundits praising Clinton’s performance, various online polls showed that most people felt that Sanders had actually won the debate.

In this latest speech Sanders attempted to fully set out what he means by democratic socialism. In his words: “Democratic socialism means that we must reform a political system that is corrupt, that we must create an economy that works for all, not just the very wealthy”.

He recounted that many of the country’s most cherished programmes, and rights such as social security, the 40-hour work week and the minimum wage were once attacked for being socialist and “now have become the fabric of our nation and the foundation of the middle class”.

In his view, continues a history of American progressivism – updating the legacy of Franklin Roosevelt’s New Deal. “Real freedom must include economic security,“ according to Sanders. "That was Roosevelt’s vision 70 years ago. It is my vision today. It is a vision that we have not yet achieved. And it is time that we did.”

New frontier

Still, some on the left challenge Sanders’s socialist credentials. His policies read like a liberal democratic wish list not a complete overhaul of society’s economic relations. Sanders has thus been referred to as a “Democratic Socialist Capitalist”, with one British observer pointedly asking: “Is Bernie Sanders really a socialist? Or just redefining socialism for America?”

These critiques miss what makes Sanders’s campaign such a big deal. By explicitly running as a socialist, he is dramatically redrawing the boundaries of American politics – and what was once thought impossible is now not only considered possible but increasingly plausible.

Sanders’s ultimate goal thus to make socialism a mainstream US value. As one commentator presciently noted:

From the days of Chartism and Progressivism to the civil rights era, such movements have rarely triumphed in national elections. But when the history books came to be written, that turned out not to matter so much. The movements changed the terms of the political debate. Sanders, in his own irascible way, is trying to do the same thing.

It is as much, in this respect, a democratic moment as it is a socialist one. According to political theorist Aletta Norval, democracy is much more than election or a set of procedural or liberal values; it is the identification with and continual reactivation of our ability to transform our society to become more equal and just.

If more and more US citizens are open to hearing from socialists – once seen as the mortal enemies of “freedom” and all things “American” – what else might they willing to consider? Sanders’s socialism is “breaking the mould” of established US politics and expanding the limits of its democracy. Indeed, he is proving that in 21st-century America, socialism is no longer the taboo it once was.

Peter Bloom does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.