"Powerful dissent:" the "coruscating guitar solo" of Supreme Court commentary

On the "powerful dissent" question, I would point to two sources to help better understand the phrase, other similar phrases, and their role, which I think of as lying somewhere between actual communicative effort and clearing one's throat, with a heavy added element of demonstrating the writer's status. The first is this glossary by Derek Muller, which helpfully explains "the jargon that usually accompanies Supreme Court analysis."

The second, a little further afield, is a wonderful book, The Rock Snob's Dictionary: An Essential Lexicon of Rockological Knowledge. Although a good deal of it is simply a helpful guide to things and people, often arcane, that rock snobs like to invoke (e.g. Van Dyke Parks, the Nuggets anthology, gated reverb), it also offers helpful information about the kinds of cliches that have been a staple of music critics' writing for years: "Seminal," "angular," "coruscating," and so on. (Co-author David Kamp provides a similar service for film snobs in another fine book.) As Michael Azerrad writes of rock cliches, such jargon "can make a writer feel authoritative—and it can also fool some readers into thinking the writer is authoritative." (The quote is from a book, but the link is to an article about Azerrad in Slate--appropriately enough, since Slate's house style is the confident assertion of dubious authority.) But it can also become mere habit.  

Is the guitar solo actually "coruscating" or "liquid?" Is the song truly "plangent?" Was that concert the writer attended really "incendiary?" Who knows? Sometimes even the writer doesn't. In many cases the writer thinks something like that is true, and is trying to get a sincere message across. Very often, they want to sound as if they have reached a firm judgment, and impress or cow the reader with that fact, even (or especially) when they clearly lack the wherewithal to assert such authority. But often enough this language is just a reflex, like coughing, or a sign of laziness.

"Powerful dissent," like the phrases listed in Derek's glossary, is basically that, but for "Supreme Court snobs"--those whose getting and spending of cultural or financial capital consists of the frequent delivery of evanescent popular or academic commentary about judicial opinions and other legal developments. Such phrases should not be assumed to be dishonest or esoteric. Those who use them may be banal but sincere. These cliches' role in asserting authority, both to overawe the reader and to get ahead in the writers' own status competition, should be noted, and both the authority and the opinion should be treated with skepticism. Beyond that, though, these phrases generally should simply be ignored, and writers should generally omit them.