My sense from lurking on the militia lists and debating offlist with vets that circulate the urban legend about Jane Fonda's visit to the POW camp, is that ther is a substantial current of hostility to the ruling class, esp. it's New Frontier/Great Society cold war liberal wing, in the POW/MIA organizations. (There are two competing groups, see the H. Bruce Franklin book from a few yrs. ago that was excerpted in The Atlantic and another one debunking the claims of soldiers still being held in Vietnam by a female Washington Times reporter, whose name escapes me.)
Franklin dates the beginning of the POW/MIA miasma to the early 70's with H. Ross Perot getting the attn. of the Nixon White House. See the Haldeman Diaries.
An aspect of the Perotian angle is the Richard Armitage connection. Back in '92, when Perot self-destructed, one factor in the conspiracy theories he blathered about was allegations about how Armitage had double crossed the POW/MIA rescue missions in his role as Pentagon point man in the Nixon days.