Since Senator Bernie Sanders, I-Vt., launched his campaign for president this spring, he has gone from being a fringe candidate of the left to a serious challenger of Hillary Clinton, who has long been considered a shoo-in for the Democratic nomination. When Sanders started gaining traction at the beginning of the summer, most shrugged him off as the new Ralph Nader, or even the Ron Paul of the left, an insurgent who would attract a dedicated but slim following.

Today, these comparisons are looking less accurate, and Sanders is no longer a fringe candidate. Last week, the Sanders campaign released its fundraising results for the third quarter of 2015, and not only did it nearly match Clinton’s third quarter results in cash, but broke the fundraising record in small donations. Indeed, the Sanders campaign has reached one million individual donations faster than both of President Obama’s historic campaigns (in 2008, Obama didn’t reach one million until February).

As one would expect, as Sanders has surged, the American right (and center) have gone from ignoring him to attacking him, and the barbs have been predictable indeed. The most common sound something like this: “Socialism has already been tried and it failed,” “There is no free stuff,” “He wants to steal from the job-creators.” Of course, these are familiar attacks that have long wielded against the Democrats, but with a man who does not shun the “socialist” label, they have become even sharper.

First things first: The word “socialism” has become so freely used by the right that it has all but lost the meaning that it once possessed. Since even before the Cold War, the word socialism has been a pejorative in America. When people on the right say, “Socialism has already been tried,” they are by and large thinking of 20th-century communism in the East, i.e., a totalitarian state with a centrally planned economy. If this were the sole definition of socialism, then these anti-socialists would be entirely correct. When considering 20th century communism, it is clear that centrally planned economies without markets do not work in the long run (and black markets become an inevitable feature). At this point in history, markets are necessary for human innovation and wealth creation. But as the economist (and communist, according to Bill O’Reilly) Robert Reich points out his his new book “Saving Capitalism,” the free market vs. government debate is mostly pointless. In order to have a functioning market, there need to be rules, and for rules of the market there needs to be government; the real debate should be whether those rules are working for everyone or just the wealthiest individuals and corporations.

The point is, “socialism” does not necessarily mean centrally planned economies, as most on the right believe. The original definition of socialism was something like this: the collective ownership of the means of production and distribution. In this sense, worker-owned businesses (i.e. worker co-ops) are very “socialistic,” and Sanders has appropriately put forth a plan to increase worker ownership. The word socialism can also mean “Social Democracy” — this is what best describes Bernie Sanders’s philosophy — which involves a market economy with socialistic programs. The most common example of this sort of economic system can be found in the Scandinavian countries, which have hardly “failed.” Indeed, Scandinavian countries have all been previously ranked among the highest in the world when it comes to “ease of doing business,” “global innovation,” and “prosperity.”