Image Gallery: U.S. Presidents
Image Gallery: U.S. Presidents

Diners have become customary meeting places for politicians and media members to discuss issues with Iowa residents. Here, Democrat Howard Dean (left) chats with a local in Mason City on the campaign trail in December 2003. See successful campaign winners in these pictures of the presidents.

Shaun Heasley/Getty Images

During the fall and early winter of every fourth year, the United States turns its full attention to the state of Iowa. The Des Moines Register newspaper gets the kind of political clout that The Washington Post or The New York Times do when its editors reveal which candidates their paper officially endorses. Average Joes and Janes are interviewed by out-of-town national correspondents over coffee and pie in the local diner about what issues are most important to them. And almost every candidate in the presidential race virtually moves to the state to spend months campaigning throughout Iowa.

Iowa's caucus draws a lot of attention to an otherwise quiet, largely agricultural state. The Iowa caucus can be difficult to explain quickly, but once you understand the process, it may be more simple than you think. Learn more about how caucuses work.

Iowa doesn't necessarily represent a diverse cross-section of America. And although Iowa is one of the few states to hold a caucus, the other 49 states hold similar ballots, generally primary elections to choose the state party's nominee for president of the United States, which it will present at the national party convention. Yet the votes cast by the residents who turn out for the Iowa caucus are so highly coveted that news agencies and political organizations take frequent polls to find out what the Iowans are thinking. Why is Iowa so important?

The simplest answer is that Iowa is the first state in the nation to have a chance to show its support for candidates. Sen. George McGovern, the Democratic contender in the 1972 election, explained the significance of Iowa like this: "Iowa is terribly important. It's the first test in the nation, where we get any test at all" [source: University of Iowa].

That test comes from real, everyday voters. The level of support a candidate receives in Iowa gives a reasonable indication of how they will perform with the rest of American voters. If middle-American Iowans support a candidate, then that candidate has a chance with the rest of the nation. The results from the Iowa caucus tell a candidate whether his or her platform is desirable. It is the first chance for a campaign to find out if its message is affecting voters -- should the campaign stay the course or change tactics? And the Iowa caucus is so important that some candidates bow out of the race if they do poorly in Iowa.

A strong showing in Iowa also sends a message to the national party leaders. Each party seeks a strong contender for the White House, and a good response from Iowans helps cement a candidate's chances to win the national nomination. Being first in the nation certainly is important. But Iowa wasn't always first, and the votes cast by its residents in the caucus weren't always so important.

In 1972, the Democratic Party changed its scheduling, and Iowa became the first state to hold its caucus. The resulting attention for the Democrats was great enough that the Republican Party also made Iowa first in the 1976 election, and since then, Iowa's importance has grown each election cycle.

But to say that the importance of the Iowa caucus is entirely due to its status as first in the nation would be a mistake. Political analysts point to another factor that bolsters Iowa every four years. Read about that on the next page.­