William:

… the decentralized republicanism advocated by Jefferson ….

You forgot to add an important qualifier. What you no doubt meant to say was “the decentralized republicanism advocated for white people by Jefferson.”

The system of rule that Jefferson advocated, and personally instituted, for black people, was not “decentralized republicanism,” but rather hereditary, personal, absolutist tyranny–tyranny of a form almost unparalleled in human history for its invasiveness, immiseration, and ruthless brutality against its unwilling subjects.

Libertarian outreach by whom? By me in particular or by libertarians in general?

If the former, then I would find libertarian outreach to leftists much more palatable for me to do than libertarian outreach to white supremacists, because I know how to talk to state leftists in a way that some small number of them will find convincing, whereas I don’t really know how to talk to white supremacists in general, let alone statist white supremacists in particular, and I think it would be extremely unpleasant to learn.

If the latter, then I have much weaker preferences, because I think generally if people are going to do outreach they should specialize in what they are best at. But I would suggest that outreach to state leftists may be more likely to succeed in the long term than outreach to state white supremacists, because both of them tend to share the common cognitive or moral vices of statists (majoritarianism, legalism, constitutionalism, contempt for private property rights), but the state white supremacists tend to add some peculiar vices of their own on top of that (e.g. violent racism or xenophobia). Turning state leftists in an anti-state direction tends to produce anarchists, whereas turning statist white supremacists in an anti-state direction tends to produce paleocons at best.

In either case, I’m not sure what this has to do with the question of whether racism or majoritarianism is (1) more offensive, or (2) more dangerous. I’d rather have dinner with a polite absolute-monarchist than with a very rude individualist anarchist. Not because I think that rudeness is worse than absolute monarchy, but rather because other factors enter into my decisions about who I should dine with. Similarly, decisions about who you should reach out to in your propaganda are not necessarily decided solely based on whose deviations from your position you consider to be the least dangerous or destructive.

Kennedy,

In that is it any more offensive or dangerous than a reverence for majoritarian democracy?

Maybe more offensive; probably not more dangerous. How offensive a particular view is, on the whole, depends on a lot of factors, not merely how dangerous it is to individual rights. Vices aren’t crimes, but they are vices, and sometimes a vicious attitude merits taking offense.

Nobody gets atwitter about advocacy of democracy, so why should racism be any more alarming?

I don’t know what counts as getting “atwitter” or what domain you’re quantifying over when you say “nobody.” Most libertarian writers that I know are fairly contemptuous of majoritarian democracy. Off the top of my head, I can think of at least three libertarians whose criticism of Ron Paul (Micha Ghertner’s, Wendy McElroy’s, and Brad Spangler’s) has specifically revolved around how the campaign promotes the myth that freedom can come about through majoritarian democracy.

As for Long, as far as I know, his position is not that racism is somehow worse or more alarming than political majoritarianism. The claim is just that racism is objectionable from a libertarian standpoint, not that it’s more objectionable than something else.