ABC's Z. Byron Wolf ( @zbyronwolf ) reports:

Stock Change - Santorum is up 11 percent in the political stock market. But his value for the nomination is still about the same as Jon Huntsman and Rick Perry's - mid-30s. More at http://otusnews.com

Dust off your Muskie and take our Politics and Primaries Quiz - Sample - Which Republican won the Iowa caucus only to lose the nomination and then, 8 years later, lost the Iowa caucus before winning the nomination? http://abcn.ws/tzYHhA

Iowa Caucus Viewer's Guide - Rick Klein says Romney is already a winner: "The judgment of some 120,000 Iowa Republicans is unlikely to lead directly to any candidates dropping out. The compressed early calendar means other contests loom for all of them, and the prospect of two debates in New Hampshire over the weekend can give even the most beleaguered candidacy hope. But functionally, candidates who had once banked their hopes on strong Iowa showings cannot afford to slip too far down the ladder. Finishes of fifth or worse for Rick Perry or Michele Bachmann could effectively doom their candidacies, even if they continue to march on to South Carolina and beyond, as both are vowing to do. http://abcn.ws/t8OY2 t

The second-to-last Good Morning Iowa - From Shush Walshe, who has been owning the Hawkeye State for months - http://abcn.ws/rM1gAd

Santorum on '06 Loss, Contraception - Rick Santorum tells Jake Tapper he lost in 2006 because it was a bad year for Republicans. And he still supports the right of states to outlaw contraception. More of that on World News.

Pile on Santorum - Rick Perry, who, along with his supporters, has spent more money in Iowa on TV ads than all the other candidates combined, dubbed Santorum as "part of the problem." Referring to Santorum's vote as senator to raise the debt ceiling, Perry suggested that when it comes to the rising national debt, he is worse than President Obama. The final day of caucus campaigning includes a pile on Santorum: http://abcn.ws/tOK0bU

New Newt - Gingrich tells Jon Karl he's going to hit Romney every day after Iowa. Romney, he says, is too liberal and cannot win the nomination. "Everything we say will have Romney's quote, Romney's videotape, Romney's record; it'll all be based explicitly on Romney," Gingrich said in an interview in Independence, Iowa… "Romney is, in the end, in a culturally hopeless position," Gingrich said.  "He's a Massachusetts moderate in a conservative party." http://abcn.ws/uxQepU

Newt Plans Freddie Mac Attack - Gingrich tells Jon Karl it was a mistake not answer Freddie Mac attacks. "We have a great story". He'll tell it an ad soon abcn.ws/vAD5Qu

Memory Lane - Past winners and losers of Iowa caucus - only three of the non-incumbent caucus winners have gone on to win the presidency. (Barack Obama, George H. W. Bush and Jimmy Carter) - http://abcn.ws/rYmkj8

Flashback - Obama's Iowa Closing Argument in '08: 'I Won't be a Perfect President' - More from Devin Dwyer: http://abcn.ws/vlen4y

How tiny Iowa took over U.S. polittics - Amy Bingham looks at how the caucuses became the caucuses. http://abcn.ws/vwNoDJ

Bracketology and "January Madness" - Matt Dowd again channels sports to explain politics. Dowd: For most of this election cycle, the No. 1 seed has been Mitt Romney, the former Massachusetts governor.  He has the campaign experience (he ran for president four years ago), his staff is well-organized and smart, and he has performed well in debates and on the campaign trail.  Even when the flavors of the month have come and gone, he has remained in either first or second place every step of the way. Is Romney the inevitable nominee as many are now suggesting?  I would say he is the likely, but not inevitable, party choice.  He still has two things to prove in this process.  First, he has not come under sustained attack by any of the other candidates, as each of his major rivals has. When that day comes, and it will, it will test his and his campaign's acumen and sustainability. http://abcn.ws/uYa0zE

Duggars for Santorum - The most unexpected endorsement of the day when the ? of the 19 family members in large reality TV family the Duggars en masse endorsed the surging Rick Santorum. http://abcn.ws/usGm8o

Rick Perry Says Bachmann, Santorum Lack National Organization to Continue - http://abcn.ws/souvRu  … Compares Campaign to a Marathon, Iowa Equals Mile One - http://abcn.ws/sGeWhi

ABC's Sarah Parnass ( @wordsofsarah ) contributed to this report.