In the past seven months of the Republican presidential campaign, there have been more than a dozen debates and countless polls. Nearly every candidate has enjoyed the spotlight as a front-runner.
Today, the nominating process kicks off in earnest as Iowans gather in schools, churches and neighbors' homes to vote.
Having covered caucus campaigns since 1976 for the Des Moines Register, I'd like to clear up some misconceptions about Iowa voters and the state's role in the race for the White House:
1. Iowa voters don't represent the United States.
Not all New Yorkers are rude, not all San Franciscans are gay, and not all Iowans are farmers.
Of Iowa's 3 million people, about 90,000 are farmers, and of those, 48,737 list farming as a principal occupation. Iowa's manufacturing and financial services industries contribute far more to the gross state product than does farming.
So media caricatures of snaggle-toothed hicks from an "American Gothic" painting don't fit.
The state is 91.3 percent white, while the country is 72.4 percent white. But even these homogeneous demographics helped Barack Obama when he won the 2008 Democratic caucuses.
His victory proved to a lot of people -- especially African-Americans he was courting -- that he could attract white votes.
While small, Iowa is traditionally one of a half-dozen battleground states. In the general elections of 1996, 2000, 2004 and 2008, the Iowa popular vote closely tracked the national vote.
Activists from each party attend caucuses, and they tend to be similar to the activists in their parties around the country. Among Democrats, that means lots of people who are prolabor and antiwar, and many who are concerned with social justice.
For Republicans, it's social and fiscal conservatives, foreign policy hawks, Second Amendment conservatives and libertarians. The Iowans who show up on caucus night look a lot like the people on the floor of the national conventions.
2. Retail politics is king in Iowa.
The one-on-one retail politicking that marked earlier campaigns has gone the way of the corner store. The days when a candidate such as George H.W. Bush could bounce around Iowa in a station wagon with a driver, an aide and a reporter are gone.
"Retail politicking" now includes messages on websites, social media posts and trips to Wal-Mart. Add in TV commercials, and politicking here looks more wholesale than retail.
Wherever America starts selecting a president, it's a big story. Since technology has become cheaper and more portable, large groups of journalists now descend on Iowa and change the nature of the events they cover.
Every reporter in Iowa these days has a story of showing up to an event where there were more media folks than caucusgoers.
Gone are the days when journalists such as Johnny Apple, David Broder, Jack Germond and Jules Witcover would slip into the kitchen to hear what was happening in the living room. Today, there are buses disgorging reporters outside Pizza Ranch restaurants.
Just as the heat of an observer's eyeball through a microscope can change the performance of the specimen below, so, too, has media heat changed retail politics.
A candidate's every word is flashed around the world, critiqued on cable news outlets, blogs and Twitter. No more does a candidate get to munch on lemon bars with a dozen locals to try out messaging and ideas.
3. To win in Iowa, you need to appeal to right-wing activists.
Ultraconservatives are an important constituency in the Republican Party, just as left-wing liberals are important to Democrats. But hard-liners are not the whole game in either party.
For example, an October Des Moines Register Iowa Poll reported that only 45 percent of likely GOP caucusgoers described themselves as very conservative on social issues.
Even among such voters, issues such as jobs and the economy are often more important than abortion and same-sex marriage.
The more centrist candidates are often the ones who claim victory in Iowa. Mike Huckabee wasn't the most conservative Republican in the 2008 contest. George W. Bush in 2000 and George H.W. Bush in 1980 weren't the most conservative in their races, either.
In 1976, Gerald Ford beat a more conservative Ronald Reagan. Bob Dole wasn't the most far-right candidate in the 1988 or 1996 contests.
If Mitt Romney wins Tuesday, it will be because many conservatives split their votes among the plethora of candidates and he was able to assemble a center-right coalition of moderate Republicans.
Is Iowa conservative? Yes. Far right? No.
4. The weather will influence the outcome.
Iowa isn't a bunch of dirt roads. Generations before farmers cared about ethanol (except as corn liquor), they cared about getting their goods to town.
Today, Iowa ranks 14th among the states in the number of miles of paved roads, while it's 30th in population. And Iowans are used to getting around in bad weather.
It is true that in the first modern presidential caucus, in 1972, Democrat George McGovern turned in one of those media-declared unexpectedly strong showings against front-runner Edmund Muskie in part because of a bad storm.
Party centrists stayed home -- no need to risk a broken hip to help Muskie, who was going to win anyway, right? The antiwar activists supporting McGovern were more motivated. But that instance of the weather affecting the outcome has been the exception.
Ever since, there has been no indication that the weather has mattered much.
However, that doesn't stop the talk. Speculation about how the weather influences caucus outcomes generally comes from bored reporters and politicians making small talk. In terms of turnout, Iowa is usually among the top 10 states in the country for general-election participation.
And the forecasts for Tuesday call for above-normal temperatures and no precipitation. So not too many broken hips are likely Tuesday night.
5. Iowa caucusgoers take voting more seriously than people in other states.
Iowans are not the only vetters of candidates. The attention lavished on their state, and the money spent there by campaigns and the media, cause jealousy among other states. But Iowa remains first largely because the two major parties can't agree on a different way to start the process.
To bring in more states, both parties have added South Carolina and Nevada to the Iowa-New Hampshire kickoff.
Iowa gets all this attention because it's first, not because people here are any more serious about the democratic process than other Americans. And the ability of Iowans to predict winners is limited.
The more traditional outcomes of the caucuses include "winnowing the field" of candidates, as Howard Baker once described it.
Iowa may start the process, but other states finish it.
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David Yepsen, director of the Paul Simon Public Policy Institute at Southern Illinois University at Carbondale, is a former political reporter, editor and columnist for the Des Moines Register. He wrote this article for the Washington Post.