I probably get LSU as a dark horse from an outsider's perspective. As a fan, it seems they have too many flaws and have fallen too far in recent years to be capable of surprising us and winning the league. But I guess that's the point of a dark horse...people don't see them coming. But that just makes me wonder what's the point of trying to predict something that, by definition, we can't/don't predict.
Cuz it's summer and we're bored, of course

Anyway, the story on LSU, as best as I understand it, is the team should be pretty solid, but safety has something to prove and may persist in being a weak link. Actually, the entire secondary has something to prove with the way they've played the last several years, but the talent at corner at least seems to be capable of being better than they have been. And then the OL....there are talented guys (supposedly), but they're new, and how long do they need in order to allow the team to be really good? Sometimes it takes OL units an entire season, that's just the nature of the position, in which case it would be next year before they're great, and LSU's QB will be gone. And of course, LSU hasn't won an opener in 6 years. Another opening loss to Clemson wouldn't technically doom the Tigers' season, but team morale may suffer and a lot of fans are either going to check out or wane in interest. And Brian Kelly will be getting the Ryan Day treatment from fans who remain. I'm of the opinion that even if slowly, peripherally, and indirectly, fan attitude eventually affects locker rooms.
So, it's hard to think of them as a dark horse, in the sense that it doesn't feel like they're waiting to surprise me. But that goes back to my other point, if we saw it coming, we wouldn't be surprised. And I didn't think our baseball team was championship quality, so what do I know.