As the first major contest in the U.S. presidential election process, the Iowa caucuses are considered very important. Since the first Iowa caucuses were held in 1972, the winner of nine of the 18 Iowa caucuses held by both parties eventually won the nomination. 

However, while the caucuses tend to be good predictors of who will win each party’s nomination, they are poor predictors of who will win the presidency. Only three presidential candidates who won the Iowa caucuses went on to become president — George W. Bush, Jimmy Carter, and Barack Obama. Here is each president’s path to the oval office. 

Just how important are the Iowa caucuses? To answer this question, 24/7 Wall St. reviewed each primary season’s top three candidates in the Democratic and Republican Iowa caucuses since 1972 (the first year of the Democratic caucuses), and 1976 (the first year of the Republican caucuses). We relied on data compiled by the Des Moines Register, a central Iowa newspaper owned by media and marketing company Gannett. 

Because some incumbent presidents ran uncontested, the following caucuses were excluded from our list: 1984, 1992, 1996, 2004, and 2012; In these years, Ronald Reagan, George H.W. Bush, Bill Clinton, George W. Bush, and Barack Obama ran uncontested as their party’s nominee. Incumbent presidents Gerald Ford and Jimmy Carter were challenged in primaries by Ronald Reagan in 1976 and Edward Kennedy in 1980, respectively.

Uncommitted voter blocs, which are common in Iowa caucuses, were included on our list. In several cases, more delegates were undecided than were committed to any individual candidate.

Click here to see how much the Iowa caucuses matters to every Democratic presidential candidate
Click here to see how much the Iowa caucuses matters to every Republican presidential candidate