As I write this, there's a Tea Party even in Boston, complete with Sarah Palin. I'm sure there are plenty of signs about socialism, and perhaps even communism, around. Liberals have, of course, laughed at these sort of accusations -- and with good reason. Do you want to see a good example? I have a great one, in a back-and-forth between two liberals in good standing, Kevin Drum and Matt Yglesias. Both are certainly liberals; for example, on health care reform, both preferred a bill with a public option, but had no difficultly strongly supporting the eventual, compromised, bill that became law. I'd guess that they would both self-identify right around where the modal House Democrat is, ideologically.
Their topic? Airlines charging for carry-on bags. To simplify: Yglesias is for it, pointing out the potential advantages to consumers of market forces. Drum is against it, arguing that the hassle of dealing with too many choices outweighs the economic gains (FWIW, I'm with Drum on this one, I think).
Neither says anything about the government simply owning and operating the airlines. That, of course, is what socialist governments do; pre-Thatcher, British Airways was a government-owner airline.
Nor do either of them recommend a big government solution. American liberals really did used to believe that heavy government regulation was best for industries prone to monopolies, which is a whole lot of industries. In the United States, the airline industry was regulated with regard to routes and price. After deregulation (passed in 1978, under Carter), airlines started competing more, and I think it's generally accepted that the result was a lot more air travel at much lower cost.
Instead, Yglesias is all for a more vigorous market (in this case), while Drum is against it's effects, and points to mild regulations such as more effective credit card disclosure requirements, not a restoration of full price regulation of airlines. And from his post, it's not really clear that he favors government action at all; he may just not like this particular market action without seeking a government remedy. At any rate, he does, in his post, praise the 1978 airline deregulation.
In other words, liberals such as Yglesias and Drum (and Obama and Pelosi) are not socialists, and are not old-style big-government liberals. Liberals, dating back to the late 1979s, have come to accept that markets are incredibly powerful and can be harnessed to do great things. Where liberals differ from, say, libertarians is that liberals tend to be very aware that markets are artificial human creations, and therefore that setting rules of a market is, in their view, properly a function of government; and, that the power of markets is not absolute, and that another proper function of government is to be aware of potential market failure. Nor do liberals, I think, believe that markets are inherently morally good (although I don't think that anyone who I would call a mainstream liberal think that markets are inherently morally evil). Therefore, for liberals, markets are instrumental, not (as I think is true for at least some libertarians) a goal themselves.
Now, I'm talking mainstream liberals here. I do think there's a left in America beyond them; I don't think what I'm saying here applies to them, at least not in general. There are, after all, real socialists in the US, and probably some real old-style big government regulators, and all sorts of points in between. But that left is also pretty small, and I don't think it includes more than a handful of Members of Congress, at best.
But mainstream liberals as socialists? Just not happening.