His view is somewhat similar to mine, adding two excellent points:
All three reasons are legitimate, though not as significant as two additional reasons. The first is that there are now tens of millions of US citizens from nations with strong socialist traditions. For example, two of the three major Mexican parties are members of the Socialist International.
The second is that the media is dominated by individuals whose politics range the gamut from Marxian to Trotksyite.
PS: always read or at least skim the comments at VP.