Using the word "adumbrated" when you mean "outlined" or "explained" isn't merely pretentious, it's wrong. "Adumbrate" means "To disclose partially or guardedly," or "To give a sketchy outline of." But Will is just using it as a synonym for "articulated." I'm not against using somewhat obscure words, but they should either be more precise than their simpler cousins (i.e, using adumbrated when you want to say "poorly explained," or using "demimonde" to denote a seedy subculture), or more pleasing (as is the case with the word "irenic," which means, and sounds like it means, "peaceful"). But this is adumbrated for ego's sake. A decent editor should have taken it out. It does, however, give me reason to link to Jon Chait's takedown of Will's populist pretensions from a few months back.
