The case against Jindal: He has only 3 percent in the Real Clear Politics average of Iowa polls. And some social conservatives have fallen flat in Iowa — Gary Bauer in 2000 and Michele Bachmann in 2012, for example. There’s also a lot of competition for the religious vote this year. In our graphical representation of the factions that make up the GOP field — what we call the five-ring circus — Jindal shares that space with Ben Carson, Ted Cruz, Huckabee and Santorum.

But again, there’s that history of late surges. There’s also the fact that very conservative candidates have tended to outperform even their final polling averages.

And beneath the headline horse-race numbers, Jindal is making noise. His net favorability rating (favorable minus unfavorable) among Iowa Republicans is fourth-best in the GOP field, according to an average of the three live-interview polls conducted over the last month (by the Des Moines Register, Loras College and Quinnipiac University).