Senator Bernie Sanders (I-VT), Congress's longest-serving independent, is reportedly seriously considering running for the White House. This is significant because Sanders openly declares himself to be a democratic socialist – a label which has been a taboo in U.S. political culture for decades.

But while Sanders will likely be attacked for identifying with socialism, it has a long history of being used by the reactionary right as a smear. In fact, that history pre-dates the Civil War. History blogger Matt Karp searched the Congressional record and found the very first instance that the word “socialism” was uttered in Congress. He found that the first time anyone used the phrase was when a North Carolinian congressman used it to attack opponents of slavery:

As far as I can make out, the first reference to “socialism” on the floor of Congress came from North Carolina representative Abraham Venable in July 1848. During a debate over the Wilmot Proviso, Venable indulged himself in a familiar litany of destructive Northern manias, which ranged from “the wicked schemes of Garrison” to “the wild excesses of Millerism, and of Latter-Day Saints, the abominations of Socialism, and of Fourieriesm … and all the numerous fanaticisms which spring up and flourish in their free soil…” […] This kind of pro-slavery, anti-Northern rant was the context for most mentions of “socialism” in Congress during the next several years.

As Karp notes, the “socialism” smear continued to rear its head during the next year leading up to the Emancipation Proclamation, as pro-slavery advocates warned that if abolitionists succeeded in ending the South's ownership of human beings, they may soon also end private ownership of massive industries like banking.

After the end of slavery, conservatives continued to invoke socialism to oppose all kinds of progressive reforms. In the early 20th century, the Congress, prodded by what was indeed an independent socialist movement and various other labor forces, banned child labor. But after the Supreme Court struck down the ban, arguing it violated state's rights, Congress debated a constitutional amendment to ban the practice instead (which required a larger threshold of votes to pass). One senator who opposed to the ban claimed that the child labor amendment was really about placing socialism “into the flesh and blood of Americans.”

When Franklin Roosevelt (under whom the previously mentioned ban on child labor finally went through and was not struck down by a conservative Supreme Court) advocated for the Social Security system, the American Medical Association (AMA) opposed his push, saying that he was trying to enact a “compulsory socialistic tax.”

One of the most prominent uses of the socialism smear was when Lyndon Johnson was pushing for the enactment of Medicare, the single-payer health insurance system for the elderly. Ronald Reagan, then a prominent actor and not a politician, appeared in audio recordings for the AMA Operation Coffee Cup – which organized Americans to oppose the health care push. “One of the traditional methods of imposing statism or socialism on a people is by way of medicine,” warned Reagan in the advertisement.

All of this begs the question: if all of these major reforms that are today virtually uncontroversial – few ever call for the total abolition of Medicare and Social Security, or for re-instating child labor or slavery – were decried as socialism, maybe socialism isn't so bad after all?

There is evidence that American public opinion is starting to warm up to the term. In 2011, Pew conducted polling finding that, among Americans age 18-29, 49 percent of them had a positive view of socialism, whereas 43 percent had a negative view. Meanwhile, among the same age bracket, 46 percent had a positive view of capitalism, while 47 percent had a negative view of it. While the overall views of Americans remained decidedly negative – with 60 percent holding a negative view of socialism and just 30 percent holding a positive view – this generational difference may point to shifting attitudes among future generations.

It may be just that shift in perspective that Sanders can tap into if he decides to seek the presidency – and a legacy of “socialism” that gave America some of its most treasured social policy reforms.