When a candidate is considered a contender--when he's polling high enough and competitive enough to be taken seriously--it's relatively easy for voters to coalesce around him. This season, we witnessed candidates like Rick Perry, Herman Cain, and Newt Gingrich skyrocket in the polls once they reached that threshold.
The trouble is that it takes a long time to reach that threshold when you're starting from near-zero in the polls. As we discussed a few days ago, even as skilled a debater as Mike Huckabee took a couple months to cultivate his following enough to reach contender status in 2007. This is because going from 0% to 15% is a slow feedback loop: People watch the poll results and gradually become more likely to support a low-poller whom they like as he goes up in the polls. Given the fact that new polls are only released once every few days at best (at worst, once every few weeks), and the fact that it takes awhile for a candidate's rise to filter into the media, it can be an arduous process. The good news is that once it's done, the payoff is big.
This brings us to Rick Santorum. He is only just now approaching the threshold. He's not quite there yet, polling at about 10%. That's even worse than it looks, as Santorum tends to be fifth or sixth due to Michele Bachmann and Rick Perry polling at about 11 or 12%.
Unfortunately for Santorum, Iowa wasted nearly three months by flirting with the disastrous candidacy of Cain and the ill-fitting candidacy of Gingrich. Iowans have even paid attention to Ron Paul. Now, with the bottom of the barrel fully scraped, it's Santorum's turn. Given a few more weeks, he might be the next candidate to skyrocket. But voting takes place next Tuesday. Santorum would probably give anything for another month to be added to the pre-Iowa season. His only hope is to do better than expected. Even losing in Iowa, placing above Gingrich would give him some ammunition for a desperate attempt to become the Anti-Romney in South Carolina.