Klavan is all over the place in his examples, seeming not to recognize any private-to-public gradations governing speech. A guest at a private dinner party and a talk-radio host all appear to be operating in the same flattened social space - not a view of society I'd describe as "conservative", and one easily colonized by the incontinent emotionalism of the leftists, and the malice of the thought-police.
What freedoms of expression you might allow yourself in various private spaces - particularly as a guest in someone's house - are not the same as the freedom one has (or rather, should have) in neutral, public space. (I've marked down as hopeless boors people with whose every shade of political opinion I agree - because they were bloviating, hectoring jerks who couldn't fathom that any social situation wasn't all about them, and that the duties of a guest include attention to what the host might or might not want going on in his house and at his table.) Klavan confuses the discretion a well-mannered person might exercise out of respect for his host with the morbid cult of public sensitivity and apology, a cult which has nothing to do with good manners and everything to do with cowardice and confusion.
That one might feel suffocated or irritated beyond endurance in certain private company is not a justification for distressing one's host. A private dinner party is not a neutral public space. (Though one would not be amiss in angling for invitations from more wide-ranging hosts.) That assorted grievance-mongers, pollyannas, charlatans, and half-wits emote mindlessly in response to fact, or rational argument about the facts, is not a justification for cowardice and groveling. The space for public debate is not a private dinner party or a boudoir. The louts raised in the pc-barn should never be allowed to get away with the claim that it is.
That inability to make "a time and a place" distinctions leaves Klavan accepting the judgment of "boor" from categories of people among whom one ought to have a more expansive freedom of expression - poker buddies, tennis partners, and, yes, friends - rather than passing righteous judgment as a civilized man on their own primitive, insular, crabbèd, boorish ways.
He is also more naïvely charitable toward "conservative politicians" than the limpest of "root causes" social workers:
This, I believe, is the reason conservative politicians so often lose their nerve, why they back down in debate even when they’re clearly right. No one wants to be condemned as a brute—especially not conservatives, who still retain some vague memory of how worthy it is to be a lady or gentleman.
Ahem. A "vague memory of how worthy it is to be a lady or a gentleman" would more likely fill them with a "vague memory" of what a sense of shame felt like. What's behind all that apologetic backing down is far more likely shamelessness. Not "I do not wish to be seen as a brute" but "I do not wish to lose money, office, and perqs".
The problem is not and never has been that having good manners must interfere with acknowledging the truth. By suggesting that it is, one is pandering to the cretinous lack of judgment that propels its sufferers into confusion or rage at social rules about "a time and a place for everything". Thus the "love of truth" is mixed with and debased by the preening thuggery of "keepin' it real", as if Larry Summers's attempting to open inquiry on the subject of sex differences in scientific aptitude is of a piece with some talk-radio boor's trash-talk. Klavan is correct to say that there are things "greater than courtesy". But if both Summers's speculations about women in science, and insulting comments about someone's appearance, accurately illustrate your definition of "discourtesy", you've been spending too much time in lefty charm school.
I don't think we're going to advance the battle for "the preservation of Western rationalism and liberty" by accepting the "bad guys" confusion of courtesy with obsequiousness, with its concomitant confusion of real debate with consensus-seeking.