Updated

With 40 days to go before Iowans cast their votes for the GOP presidential nominee, here are my best bets for the top three winners of the 2012 Iowa Caucuses: Mitt Romney, Ron Paul, and Newt Gingrich.

Romney has been trailing in Iowa for most the year but his campaign is now shifting gears. His smart campaign team has decided to begin investing the money needed to build the big campaign organization necessary to get people to the caucuses. And right now it looks as if that money, plus television ads showing a less buttoned-up Romney capable of sharp attacks on President Obama, is the whip to drive Romney to the front of the pack.

The Romney campaign had been willing to cede Iowa to more socially conservative candidates. The Evangelical Christians and hardcore conservative activists who attend the caucuses have never trusted Romney. His 2008 campaign spent $10 million in Iowa only to finish far behind former Arkansas Gov. Mike Huckabee.

But a Des Moines register poll from late October had Romney statistically tied for first place in Iowa with Herman Cain. And Cain has since seen a sharp drop in his support.

Former Speaker of the House Gingrich is now the alternative to Romney and social conservatives have reservations about Gingrich’s personal history and policy positions. Gingrich is also in debt and is only now putting a campaign structure on the ground in Iowa.

That means the path is clear for Romney’s campaign dollars to push him to victory. And Romney has reason to believe that a win in Iowa, before going into the New Hampshire primary, where he has held a consistent lead for months, will have intimidating political impact on the race.

A win in Iowa could give him insurmountable momentum before the campaign heads back to difficult terrain for him in socially conservative South Carolina.

And the Romney campaign has the money to spend. So, with a month to go Romney is looking to be the smart bet to win in Iowa.

Now who is the best bet to be the place horse – the candidate most likely to finish second in Iowa?

Of all the candidates, Ron Paul probably has the most enthusiastic and steadfast supporters. His Internet-based fundraising and organizational machine has kept him alive in the polls. His team is well organized in Iowa.

Paul came within 200 votes of winning the Ames Straw Poll back in August. He finished a close second behind Michele Bachmann who has since dropped to single digits in Iowa.

Paul, the 74-year-old Libertarian icon has stressed that he wants to be the Republican nominee for president in order to bring the party back to its conservative ideological roots. He is not running for re-election to Congress and this may be his last hurrah.

With a fragmented GOP contest and a comparatively weak front-runner, he is becoming the safe haven for Iowans who don’t want to give Romney the crown. He is not a social conservative but he is in line with Tea Party discontent with the status quo and a terrific protest vote.

Smart money is beginning to load up on Ron Paul because he is looking very strong for a second place finish as we head into the final stretch.

And now for the final entry in the contest to finish in the top three in Iowa: Gingrich.

He has surged to the top of the polls in the last week. Propelled by his strong debate performances and signature skewering of the liberal media, the Republican Party faithful are giving him a second look.

On the ground in Iowa, the lack of money and lack of political organization are holding Gingrich back. But Republicans nationwide, including those in Iowa, highly respect his intelligence and his willingness to put forward bold, original ideas.

The odds are against him winning Iowa only because of all the problems with his family life, his policy flip flops on global warming, his acerbic attack on House Republicans for right-wing social “engineering” and the very big money he earned playing the inside Washington game with conservative demons such as Freddie Mac.

But Gingrich is right when he brags that conservatives who can’t stand President Obama relish the prospect of sending the voluble, pithy, former professor to debate him. Gingrich is capable of launching zingers against the President that will thrill the right-wing.

In every Iowa Caucus since 1972, the eventual Republican nominee has finished in the top three -- win, place or show. Gerald Ford, Ronald Reagan, George H.W. Bush, Bob Dole, George W. Bush and even John McCain all had to clear this first hurdle of the Republican contest before they could go on to be their party’s nominee.

For GOP presidential hopefuls who finish out of the money in the Hawkeye State, it is a good bet that they will soon find themselves out of the race entirely.

It also true that the result of the Iowa Caucuses do not always match up with the national polls.

In 2008, Mike Huckabee won the Iowa caucuses with 34% of the vote, Mitt Romney came in second with 25% and Fred Thompson and John McCain tied for third place, each with 13% of the vote.

At the time, the national polls still showed Rudy Giuliani as the clear frontrunner with Fred Thompson and Mitt Romney rounding out the top three. McCain was stuck in fourth place. Recall that McCain did not compete in Iowa in 2008. When he did better than expected in the Caucuses, it gave him the momentum he needed to seal the deal in New Hampshire and South Carolina.

Another point to keep in mind before Iowa is that the most recent Real Clear Politics average of the national polls shows that none of candidates vying for the GOP nomination win in a head-to-head matchup with President Obama.

New Jersey Governor Chris Christie had some characteristically blunt advice for Republicans last week.

“I think anybody who underestimates the president over the next year, underestimates him at their own peril. These guys have shown that they don't know a hell of a lot about governing, but they know how to campaign. They know how to campaign” said Christie, a Romney supporter.

“I have watched the president now since he's gotten into more campaign-styled things, he gets more energized, he gets more animated, he's off the prompter…speaking from his gut. That's the person that people elected in 2008. That's the guy.” Christie added.

Let the fun begin.

Juan Williams is a writer, author and Fox News political analyst. His latest book is "Muzzled: The Assault On Honest Debate" (Crown/Random House) which was published in July.