I suppose any Libya-intervention skeptics who maintained that we could not possibly defeat the regime should be embarrassed. But I can’t think of anybody to whom that description applies, and John Yoo casts a wider net than that. For him, it appears that anyone who believes that presidents tend to have too expansive a view of their own powers under the Constitution qualifies as an “isolationist.” That seems like an idiosyncratic definition. But in any case, it’s hard to see how anything that has happened in Libya could possibly settle the constitutional question either way.