Check out this short documentary on the political and economic influence of Rev. Moon (of Moonies fame).
Pretty interesting. On the surface it's plausible that some Congressmen thought they were just honoring a religious leader, like a mayor presenting someone with the key to the city, but of course living in Washington they all know who he is. When I was a kid growing up in D.C., everyone knew he owned 7-11, but he seems to have mostly stayed out of the headlines since then.
Freedom of religion requires we treat religious leaders with a certain amount of respect, but the separation of church and state should prevent the crossing of a certain line into endorsement. Moon's many businesses that have government contracts may be no more corrupt than other contractors, and the fact of their ownership can not be held against them.
I would be interested to hear more about his actual doctrines. The documentary seemed to imply that he started out advocating sexual freedom of some kind, at least privately, but now recommends abstaining from sex before marriage.
The fact that the children of the mass weddings are coming of age would make a great documentary in itself: Growing Up Moon.