It's certainly appropriate that he doesn't call himself a conservative because he's obviously not.
Our atheist FReepers certainly will disagree with this, unless they think about it for a while, but...
unless there is an unchanging, objective source of the definition of good and evil, right and wrong,
there is no “conservatism” as there are no unalienable natural rights.
Without that objective, unchanging source, moral values, indeed, even “ethics”, are just a matter of personal preference. And you can’t say someone else’s “morals” are “wrong” without a circular assumption that your standard is correct.
Mr. Duke is no leftist Lurker, I can tell you that. I’ve been reading his stuff for a while and he’s hard to peg. But if I had to describe him I’d say he’s a bit like Joe Sobran. He’s ardently pro-life, anti-immigration (he even opposes legal immigration) and extremely traditional in terms of sexual mores. He’s also never boring, whether you agree with him or nor.
In what way(s) is he a closet leftist? I am interested in knowing especially because I met him once, quite coincidently, and had an extended conversation with him.
Read the essay linked in the first paragraph or my quick summary in comment# 1. He sounds better than a conservative when conservatives are content to halt a further advance by the left. He sounds like a reactionary. He wants to reverse the advances the left has already made, e.g. hate crimes, political correctness, etc.