With the exception of running for a second term, unopposed, here are the winners of the Iowa Caucuses who have actually gone on to win the presidency:
2008 – Barack Obama
2000 – George W. Bush
Let’s look at who won the presidency without winning Iowa:
1980 – Ronald Reagan
1988 – George H. W. Bush (He actually polled 3rd)
1992 – Bill Clinton (Polled 4th)
Let’s look at some winners of Iowa who did not get their party’s nomination:
1972 – Edmund Muskie (Polled 2nd behind uncommitted)
1980 – George H.W. Bush
1988 – Bob Dole, Dick Gephardt
1992 – Tom Harkin
2008 – Mike Huckabee
From this small sample of data, I would say Iowa doesn’t mean a hell of a lot.
All we have to do is ask Ex-Presidents Dole, Gephardt, Harkin, Kerry, Muskie, and Huckabee.