Supporters listen to Republican presidential candidate and former Massachusetts Governor Mitt Romney at a campaign in Marion, Iowa January 2, 2012.
Iowa is centre stage in U.S. presidential politics once again as thousands of Republicans prepare to vote for the candidate they want to see take on President Barack Obama in November 2012.
Read our latest story on the three-way split at the top, and watch how Iowa came to be centre stage in U.S. politics.
But here is a question: how well do Iowans - Republicans and Democrats - do in choosing the eventual presidential nominee?
This year, the Democrats have an incumbent president, and while there is a Democrat Iowa caucus taking place today there's no 2012 Republican-style agonizing over picking a candidate.
But previous campaigns have been different.
With the help of The Des Moines Register in Iowa, here is a look at the Iowa track record. When it comes to picking winners, do Iowans - Democrats or Republicans - always choose the candidate who will be on the ticket in November?
In contested caucuses, where there was no incumbent Democrat president who was running unopposed, Iowa Democrats chose the eventual presidential nominee in 5 out of 9 caucuses.
Twice the Democrat winner of the Iowa caucus has gone on to become president: Barack Obama in 2008 and Jimmy Carter in 1976. (In 1976, candidate Mr. Carter won the Iowa caucus when, in fact, there were more people who did not commit to any candidate than there were Carter supporters.)
In 1992, hardly any Democrat candidates campaigned in Iowa against front-runner and eventual Iowa caucus winner Senator Tom Harkin. Candidate Bill Clinton finished fourth, with only 3 per cent of the caucus vote, and went on to win the presidency.
In contested caucuses, where there was no incumbent Republican president who was running unopposed, Iowa Republicans chose the eventual presidential nominee in 3 out of 6 caucuses. Only once has the Republican winner of the Iowa caucus has gone on to become president: George W. Bush in 2000.
In fact, George W. Bush won the Ames straw poll in August 2000, followed months later by winning the Iowa caucus, the party's nomination and the presidency. This year, Michele Bachmann won the Ames straw poll, and she is expected to do poorly in the Iowa caucus.
Republican candidates who win the Iowa caucus generally do not win the party's nomination. In 1980, George H. Bush beat Ronald Reagan in the Iowa caucus. Mr. Reagan would go on to win the party's nomination and the presidency. In 1988, Bob Dole beat George H. Bush in the Iowa caucus. And this time, it was Mr. Bush who would go on to win the party's nomination and the presidency.
As one conservative blogger observed ahead of today's Republican Iowa caucus: "Got a favourite in the Republican Primary that you'd like to see in the White House? Pray that she or he loses the Iowa Republican Caucus. Then she or he will have a shot at winning the general election for the President of the United States -- history shows."
Here is a more detailed break-down of caucus results going back to the 1970s:
Iowa caucus 2008
Democrats: Barack Obama 37.6%, John Edwards 29.8%, Hillary Clinton 29.5%, Bill Richardson 2.1%, Joe Biden 0.9%, Others 0.2%
Eventual nominee: Barack Obama
Republicans: Mike Huckabee 34.4%, Mitt Romney 25.2%, Fred Thompson 13.4%, John McCain 13%, Ron Paul 9.9%, Rudy Giuliani 3.4%
Eventual nominee: John McCain
Iowa caucus 2004
Democrats: John Kerry 37.6%, John Edwards 31.9%, Howard Dean 18%, Dick Gephardt 10.6%, Dennis Kucinich 1.3%, Wesley Clark .1%, Uncommitted .1%, Joe Lieberman 0%, Al Sharpton 0%
Eventual nominee: John Kerry
Republicans: President George W. Bush unopposed
Iowa caucus 2000
Democrats: Al Gore 63%, Bill Bradley 35%, Uncommitted 2%
Eventual nominee: Al Gore
Republicans: George W. Bush 41%, Steve Forbes 30%, Alan Keyes 14%, Gary Bauer 9%, John McCain 5%, Orrin Hatch 1%
Eventual nominee: George W. Bush
Iowa caucus 1996
Democrats: No caucuses, President Bill Clinton unopposed.
Republicans: Bob Dole (26%), Pat Buchanan (23%), Lamar Alexander (18%), Steve Forbes (10%), Phil Gramm (9%), Alan Keyes (7%), Richard Lugar (4%), and Morry Taylor (1%)
Eventual nominee: Bob Dole
Iowa caucus 1992
Democrats: Tom Harkin 76.4%, Uncommitted 11.9%, Paul Tsongas 4.1%, Bill Clinton 2.8%, Bob Kerrey 2.4%, Jerry Brown 1.6%, Others .6%
Eventual nominee: Bill Clinton
Republicans: No caucuses, President George H. Bush unopposed.
Iowa caucus 1988
Democrats: Richard Gephardt 31.3%, Paul Simon 26.7%, Michael Dukakis 22.2%, Jesse Jackson 8.8%, Bruce Babbitt 6.1%, Uncommitted 4.5%, Gary Hart .3%, Al Gore 0%
Eventual nominee: Michael Dukakis
Republicans: Robert Dole 37.4%, Pat Robertson 24.6%, George H. Bush 18.6%, Jack Kemp 11.1%, Pete DuPont 7.3%, No preference .7%, Alexander Haig .3%
Eventual nominee: George H. Bush
Iowa caucus 1984
Democrats: Walter Mondale 48.9%, Gary Hart 16.5%, George McGovern 10.3%, Uncommitted 9.4%, Alan Cranston 7.4%, John Glenn 3.5%, Reuben Askew 2.5%, Jesse Jackson 1.5%, Ernest Hollings 0%
Eventual nominee: Walter Mondale
Republicans: No caucuses, President Ronald Reagan unopposed.
Iowa caucus 1980
Democrats: Jimmy Carter 59.1% , Edward Kennedy 31.2% , Uncommitted 9.6%
Eventual nominee: Jimmy Carter
Republicans: George Bush 31.6%, Ronald Reagan 29.5%, Howard Baker 15.3%, John Connally 9.3%, Phil Crane 6.7%, John Anderson 4.3%, No Preference 1.7%, Robert Dole 1.5%
Eventual nominee: Ronald Reagan
Iowa caucus 1976
Democrats: Uncommitted 37.2%, Jimmy Carter 27.6%, Birch Bayh 13.2%, Fred Harris 9.9%, Morris Udall 6%, Sargent Shriver 3.3%, Others 1.8%, Henry Jackson 1.1%
Eventual nominee: Jimmy Carter
Republicans: Gerald Ford (1st), Ronald Reagan (2nd)
Eventual nominee: Gerald Ford
Iowa caucus 1972
Democrats: Uncommitted 35.8% , Edmund Muskie 35.5% , George McGovern 22.6% , Others 7%, Hubert Humphrey 1.6%, Eugene McCarthy 1.4% , Shirley Chisolm 1.3% , Henry Jackson 1.1%
Eventual winner: George McGovern
Editor's Note: The original version of this article incorrectly said that Gerald Ford had won the Iowa caucuses in 1976. This version has been corrected.