I think Rounds is the darkest of dark horses. But I'm pretty sure Huntsman would count as a dark horse to the majority of the country and media, and at least Huntsman has shown some indication that he's interested.
I think Jindal is a "dark horse" but Huntsman is an "incredibly dark horse." If you want a "black hole horse" maybe you could look at Hoeven
I agree with most of this. I would go with Huntsman as the most likely dark horse, but Hoeven and Rounds rate higher than he does on the "obscure-o-meter", and they'd be next on my list if we're not counting Huntsman as a dark horse.....Rounds probably more likely than Hoeven.
Where I differ is that I don't think Jindal would count as a dark horse. Or maybe he would, but it depends on how you define "dark horse". I personally rate the chances of Jindal running in 2012 as fairly low. (Though if he did run, I think he'd have a good shot at the nomination.) However, for the political media, Jindal is probably the 4th most commonly mentioned potential 2012 GOP presidential candidate, after Huckabee, Palin, and Romney. So if we're going by media expectations, then Jindal is too strong a contender to count as a "dark horse" (unless everyone but Huck, Palin, and Romney is a dark horse).
Why is there virtually no one from the Senate in the mix for the 2012 GOP presidential nomination, at least judging by who's being speculated about?