Poulos wades into some thickets:
A conservative equipped with Bramwell’s Weberian rulebook, then, is left utterly out in the cold when legitimate institutions fail. A conservative or anyone else bumbling along with one of Matt Yglesias’ fig leaves, however, can at least take refuge among the shards convention, hoping to shore them up against our ruin. The coalition of the willing that invaded Iraq, the NATO coalition that bombed Serbia, and Lincoln’s Grand Army of the Republic all advanced an interpretation of legitimacy, which had its logic to it under the circumstances but also fell significantly short of real’ legitimacy. The real argument about all three of these military bodies, and the wars they fought, is whether, in the absence of true legitimacy, they were justified by power or by authority.
One favorite Oakeshott anecdote: at a National Review confab where Oakeshott was unfortunate enough to speak, his address received utter bewilderment from the muckety-mucks and Buckley proteges in the crowd. In the end, one of them mustered a question: "Excuse me, Mr Professor. But what does any of this have to do with the power of the president of the United States?" "Oh," Oakeshott reportedly replied. "The president of the United States has no power. He has authority."