I'm not sure which of the propositions he believes are true but are disbelieved by the typical Less Wronger.

Judging from his previous comments, the proposition is approximately that the political right is persecuted in all tiers of society (LW included) by the political left. It has some subpropositions about political correctness, race, war in Afghanistan, libertarianism etc. I am not sure how does he define right and left.