Speaking in Iowa last weekend, Bernie Sanders said he wants the entire country to allow people convicted of felonies to vote from behind bars, following the lead of his home state of Vermont. In doing so, he joins a long line of socialists pushing for universal suffrage.

Maine and Vermont are alone in placing no restrictions on voting based on criminal convictions. Everywhere else, felons in particular are denied the ballot during incarceration and often afterward. In ten states, it is possible for convicted felons to lose their right to vote for life.

Proponents of felony disenfranchisement laws argue that because serious crime is a breach of the social contract, it is justifiable to expel felons from the political body, even though the right to vote is generally understood as a basic tenet of democracy.

But this is a post hoc rationalization. The real purpose of these laws is political; just look at when and where they first appeared. A wave of felony disenfranchisement statutes swept the Northern states in the 1840s, just as property restrictions on white male voters began to disappear, creating a new working-class voting bloc that imperiled elite political power. Another wave swept the Southern states in the late 1860s, after emancipation of the region’s enslaved population threatened much the same.

Felony disenfranchisement has always been about keeping vote totals down among populations whose interests are at odds with the most powerful members of society. Combined with a well-oiled criminal justice machine that targets poor and minority populations for incarceration, felon disenfranchisement is a convenient instrument for managing political outcomes.

In Florida, for example, the recent restoration of post-incarceration felons’ voting rights created over one million potential new voters, most whom are poor and a disproportionate number of whom are black. Given the likelihood that these new voters will gravitate toward Democrats, it’s little wonder that the state’s Republican lawmakers are pushing back so hard.

But if disenfranchisement is a tool of oppression, the reverse is also true: expanding the vote is a vital means of empowerment for the oppressed. Socialists have long understood this, which is why for the better part of two centuries they have fought, almost without exception, for expansion of the suffrage.

One example comes from Germany in the early twentieth century. At that time, the German women’s suffrage movement was pursuing voting rights for women, but failing to challenge property requirements. This would mean that wealthier women would be able to vote alongside their wealthier male counterparts, but working-class women and men alike would be left out and disempowered.

The socialist Clara Zetkin took these suffragists to task in 1906, accusing them of being “not in favour of women’s rights, but of the rights of ladies.” She argued that the task of socialists was to pursue true universal suffrage — of women in addition to men, and of the poor in addition to the rich. If the working class were excluded, suffrage would only be a tool for wealthier women to improve their own station in elite society while simultaneously preserving their class’s domination over the poor.

“That is not the kind of Woman Suffrage which we demand,” Zetkin wrote. Working-class women “demand equal political rights with men in order that, with them, we may together cast off the chains which bind us.” For socialists, it was universal suffrage or bust.

Another example comes from the United States a few years later, when American socialists rose to defend black voting rights in Oklahoma. The state had served as a refuge for blacks fleeing the South, and for many decades black Oklahomans enjoyed full voting privileges. In 1910, their right to vote came under attack in the legislature, and the Socialist Party in Oklahoma immediately sprang into action, attempting to stop the disenfranchisement.

The battle continued for many years, but the swift action by socialists won the party the support of black leaders in Oklahoma, who in response encouraged black people to vote the socialist ticket. The state’s Socialist Party members, who were mostly white, responded, “We welcome this action on the part of the negroes, not because it will increase our voting strength in the fall election, but because the negro is part of the working class and we stand for the whole of it.”

In 1912, the Oklahoma Socialist Party explained its opposition to the disenfranchisement efforts in greater detail, stating that the “safety and advancement of the working class depends upon its solidarity and class consciousness. Those who would engender or foster race hatred or animosity between the white and black sections of the working class are the enemies of both.” Again, nothing less than universal suffrage would do.

For socialist proponents of universal suffrage, the considerations have always been both moral and strategic. First, all people deserve the right to vote because they are members of society, and socialists are committed to democracy. Second, as Friedrich Engels put it, universal suffrage is “a splendid weapon” that the working class can use to its advantage as it resists capitalist tyranny and endeavors to build a more equal world.

By calling for the enfranchisement of incarcerated people, Bernie Sanders carries on the tradition of socialists fighting for universal suffrage. He has also demanded the elimination of strict identification laws, gerrymandering, and voter purges. Since voter suppression limits the potential of suffrage where it is already legally extant, these reforms, too, are part of the fight for universal suffrage. So, too, are efforts to secure voting rights for all immigrants, including noncitizens.

As Bernie put it, when you’re in prison you’re “still living in American society and you have a right to vote,” plain and simple. It may sound like an obvious point, but the notion that people living in a society have a right to determine the direction of that society has always been debatable at best to the ruling class. And it is socialists who have forced that debate time and again.