Actually, it isn't. Don't know what your background is, but if you ever saw a communist country in action, you wouldn't likely to say that.
The "workers" never actually do "control the factory", the Party & the government does. The Party & government tells it what to produce, how much to produce, controls the access to raw materials, the staff, the output and the distribution of the goods. The "worker" is just a replaceable cog in the wheel, not "a free person". Real democracy requires that there be "free people ("demos") in order to have "democracy".
However, your point about the US being a Constitutional Republic is true.
Great read. I recall reading the planks of the KGB-supported Marxists in this country during the Cold War — methods of disrupting, weakening America from within. They sum up very nicely the agenda of today’s Left. It’s true, those who espouse this stuff are communists, even if most don’t realize it.