“The corn is as high as an elephant’s eye,” a signature line from the classic musical “Oklahoma,” comes to mind concerning the Iowa caucuses for presidential candidates.

A tall, large cornfield can conceal mischievous activities. Joking aside, corn is an important crop but only one among many. Iowa is a relatively small state, and also notably homogeneous in population.

Yet tremendous attention is devoted by the media and party activists to the caucuses. The results can significantly shape presidential contests, sometimes decisively.

In 2016, Iowa boosted insurgents in both parties. Democrat Hillary Clinton won the caucuses, but barely defeated Sen. Bernie Sanders. Sanders’ strong second place finish gave his long-shot campaign a major boost.

Sen. Ted Cruz won the Republican primary. He was already viewed as a major contender, but Donald Trump finished a strong second, giving his unusual campaign tremendous new credibility.

In 2020, the Democrats in Iowa have changed the rules for their party caucuses. Delegates to the national convention will be allocated based on precinct caucus results. A candidate must receive at least 15 percent of a caucus vote to be counted.

Iowa can catapult relatively unknown candidates to national prominence. This includes Sen. George McGovern and Gov. Jimmy Carter, who became Democratic presidential nominees in 1972 and 1976 respectively.

Iowa has been less pivotal in other elections. After investing tremendous effort, George H.W. Bush bested Ronald Reagan in the state in 1980, only to lose the Republican nomination to him. Bush did become Reagan’s running mate, and eventually president.

In 1988 Democratic Congressman Dick Gephardt won the caucuses, but Michael Dukakis became the nominee. That year, George H.W. Bush won the White House but finished third in Iowa behind Sen. Bob Dole and political evangelist Pat Robertson.

Bill Clinton and other Democratic aspirants steered clear of Iowa in 1992, deferring to home-state candidate Sen. Tom Harkin. In 2004, Howard Dean and John Edwards carried out a public battle, but John Kerry finished first and went on to become the Democratic nominee.

In 2008, evangelical Christians turned out to help Mike Huckabee defeat Mitt Romney. His message of Christian conservatism, delivered in a direct, down-to-earth style, resonated very well in Iowa.

While Democrats have nominated candidates who suddenly emerge in the public consciousness, such as Carter, Kerry, McGovern — and John F. Kennedy in 1960, Republicans have tended to choose the runner-up from the previous nomination contest. This was true of John McCain in 2008, Bob Dole in 1996, George H.W. Bush in 1988, and Ronald Reagan in 1980.

Historically, Republican primary contests have been defined in terms of so-called “Establishment” versus insurgent candidates. The primary ordeal has become important to a process by which leaders initially viewed as insurgents, for example Reagan and McCain, become generally identified as in the party establishment.

In 2016, Donald Trump upended all these traditions. Iowa provided essential initial momentum to capture the nomination. By contrast, Hillary Clinton represented the

party establishment, apparently back in control after Barack Obama’s successful candidacy in 2008.

New rules for the Democrats require announcing initial results, final results and likely delegate allocations among candidates. That along with the general breakdown in reporting the results this year weakens the Democratic Party. So far, the only winner is the Republican Party.

Iowa traditionally provides a distinctive but integral component of American political democracy. This time, a flawed system including poor organization has undercut that role.

Cyr is a Clausen Distinguished

Professor at Carthage College. His email address is acyr@carthage.edu.