I honestly do not know which kind of “bussed in” my friend meant.
However, if the 2012 Presidential elections in my corner of South Florida are any indication, it would be the Soros Variety. I saw it with my own eyes here.
The communist groups that almost always show up for these things and soon begin organizing them are The Revolutionary Communist Party and Workers World Party. Both have various offshoots and front groups. Although I haven’t looked into it, I’m sure they have launched some new fronts to deal with this and similar situations.