( CNN ) -- It has become a great American tradition , an act of small-town civics , an example of direct democracy in action where citizens get to meet presidential candidates multiple times . But it is also an overhyped media circus , which helps give Iowa disproportionate influence on who gets the Republican nomination , despite the fact that no binding delegates are actually selected . The Iowa caucuses are low-turnout , high-intensity elections . There are 2.1 million registered voters in Iowa . But the total turnout for the GOP caucus in 2008 was just 118,696 people , despite the months of media hype . Mike Huckabee won the caucuses that year with nearly 41,000 votes , beating Mitt Romney by more than 10,000 votes while being outspent considerably . That 10,000-vote margin represented less than half of 1 % of the entire state 's electorate . Overall , the state of Iowa is representative of heartland America -- 37 % registered independent , 32 % Democrat and 30 % Republican . But caucus-goers do not represent that political spread . Instead , 88 % of GOP caucus voters in 2008 identified themselves as `` conservative , '' and only 11 % described their views as moderate . Nearly two-thirds were evangelical . As a result , center-right Republican candidates who might have the best chance of winning Iowa in a general election have a hard time making inroads in the conservative caucuses . Conventional wisdom states that the top three finishers in the Iowa caucuses are all winners , with a chance to win the nomination , especially if they exceed expectations . But jowly former Sen. Fred Thompson came in third in Iowa and dropped out of the campaign . John McCain gained the endorsement of the Des Moines Register in 2008 as well as the nomination , but he did n't finish in the top three in '08 or '00 . In fact , since 1980 , the only Republican nonincumbent who has won the caucuses and gone on to win the presidency is George W. Bush . This year , we have a real horse race with no clear leader -- polls say establishment candidate Mitt Romney is in pole position , followed closely by libertarian Ron Paul and the surging social conservative Rick Santorum . Newt Gingrich 's once commanding lead has been shrunk by more than $ 2 million in negative ads , most from a Romney-affiliated PAC . Rick Perry 's invested his considerable campaign cash in a combination of in-state ad-buys and ground-game organization . Michele Bachmann 's campaign , which once was strong enough to win a straw poll in the state , has collapsed under the weight of the candidate 's considerable overreach , marked by high-level defections and rock-bottom polls . Bachmann has taken to desperately trying to compare herself to Margaret Thatcher at every stop while her campaign cites the judgment of a conservative Christian group that she is `` biblically qualified to be president '' -- whatever that 's supposed to mean . One of the real questions in this caucus is whether retail politics matters as much as it used to . Mitt Romney basically dissed the state for the first 10 months of 2011 , still stinging from his expensive rejection in 2008 . But his well-funded campaign was able to buy aspects of a statewide organization and negative ads to tear down rivals . One of the fascinating aspects of the Romney campaign is that he seems to have a glass ceiling of 25 % -- the same percent of the caucus vote he received in 2008 . The other candidates have famously traded the other 75 % of the vote over the past several months . If the deck is shuffled just right , with a number of other candidates in the mid-teens , Romney can win Iowa in this crowded conservative field . And if he wins Iowa on Tuesday night , his months-long double-digit lead in New Hampshire will solidify and he will be almost assured of winning the first two states , well on the way to winning the nomination . Additionally , he has the weight of precedent on his side : The front-runners who have conventional wisdom behind them tend to win the Republican nomination eventually , after the party flirts with a dark horse . But Ron Paul is a wild card . His supporters are by far the most dedicated , if not the most numerous . They will turn out come sleet or snow ( though the temperature is supposed to be above average ) . The January 3 caucuses are smack in the middle of winter break for universities , but Paul 's younger supporters might just come back early to vote for their hero . If Rick Santorum 's recent momentum continues , he can claim the evangelical mantle as the consistent social conservative alternative to Romney , the man he endorsed in 2008 . He provides at least one other clear point of contrast -- Santorum has been hammering away at middle class and blue collar issues , while Romney embodies the one percent of the wealthiest Americans . The most dire scenario for Romney would be a Newt or Perry surprise surge , which the polls say seems unlikely . But either of their campaigns could come out of Iowa with new momentum and at least a real chance of winning South Carolina and possibly Florida . Three out of four states by the end of January makes a candidate extremely likely to win the party 's nomination . The countdown to the Iowa caucus can now be measured in hours , instead of weeks or months . Whatever you think about the disproportionate influence this heartland state has on our politics , it can not be ignored . The presidential election year of 2012 is here . And on Tuesday night , the race for the White House will really kick off . The opinions expressed in this commentary are solely those of John Avlon .
The 2012 presidential race begins Tuesday with Iowa caucuses . John Avlon says the caucuses are low-turnout , high-intensity elections . He says worst case for Mitt Romney would be a surprise surge by Newt Gingrich or Rick Perry . Avlon : Romney could win with only a quarter of the vote .