What do Bill Clinton, George H.W. Bush and Ronald Reagan have in common?
These former presidents all lost in the Iowa caucuses, but won their party's nomination and, of course, the subsequent general elections.
What about Mike Huckabee, Dick Gephardt and Tom Harkin? They came in first in Iowa but failed to become their party's standard-bearer.
Iowa has always chosen its presidential candidates using caucuses, but the caucuses didn't achieve the significance currently attributed to them until 1972, when the Democratic Party moved the contest to the beginning of the year.