Yes, x. I concur with your last. But this is ambivalence of a unique kind. It is one that admits the independent and extra-anthropological existence of truth. Yet it doesn't deny the human participation in it. The implications of this stance are profound in the area of law.
When a reasonably good existing regime is threatened by one that manifestly isn't at all good, one ought to defend it, if only to defend one's "the good," which is possible under the good regime and impossible under the bad. But the question is how far one should go in defending it and how much of one's own detachment and philosophical freedom one should contribute to that defense. I suppose it matters how one sees oneself: as a Socratic philosopher (which seems to imply a skeptic), as a doctrinal philosopher (who tries to find foundations for what a society believes or knows to be true, good and just) or as a statesman (concerned with political action in the world).
There's much to be said for Jaffa's concern for our society and its beliefs. He sees the abyss and seeks a way to escape it, but I have to wonder whether some of the Straussians' dogmatic arrogance can't be traced back to the urgent necessity of escaping the nihilism that haunts Strauss's own teaching. Once you make the Declaration of Independence the sole alternative to catastrophe, you exclude a lot of other worthy ideas. The founders themselves clearly believed in the documents they created, but I don't think the question of nihilism occupied them as much as it did twentieth century thinkers. For the most part, they were more inclined to let their experiment prove itself than to demonstrate its universal validity and urgent necessity or to impose it on others.
Another link here. The Strauss list is also a good place to resolve perpetuate confusions about Strauss.