Rick Santorum didn't jump to the front of the race. He tied Romney in Iowa. There's a difference.
Santorum will not be nominated, or elected. This is his time to shine, and he'll place fourth or fifth in New Hampshire, which will be the dose of reality he and his supporters won't care for.
Sorry to say it--because I enjoy the show as much as the next man--but it's over except for the fighting. Santorum's just the latest thorn in Romney's side. He won't last. Santorum's politics don't play well in New Hampshire. He may sputter on a little longer--South Carolina, maybe, and hope for a good finish there to propel him into deep southern states. (Rick Perry's hoping for the same thing.)
Oh, and if Michelle Bachmann had any sense or dignity left she'd drop this quasi campaign of hers. Iowa rebuked her last night. She never really ran an actual campaign...it was always more of pretend to run for president, like a kid playing dress up. But she has zero support on the ground in NH, no staff, and should stop kidding herself. She'll place dead last here.
And Rick Santorum won't do much better. Iowa is the high watermark of his candidacy.