Ever since I learned about the Iowa Caucus, the one burning question in my mind has always been thus: "Why does Iowa get to go first?" The answers are varied somewhat but they all essentially boil down to this: "Iowa is the most accurate cross-section of America and is a great predictor of Party Nomination winners."
The first part of this answer doesn't pass the smell test with me. Iowa an accurate cross-section of America? Really? Iowa is almost completely Rural. It doesn't have a particularly large population. It doesn't ever seem to matter in the general election. It is historically a swing state, yes, but its 6 electoral votes are rarely an attractive prize when there are much more populous swing states like Ohio and Indiana nearby. In fact, if there were any state that provided the best cross-section of America, it'd be Ohio. It bristles me to say that as a Michigan native, but the fact that no President has won without Ohio in over half a century is hard to argue with.
The second part of the pro-Iowa claim (that it predicts primary winners) takes some examination. So let's do that. Since the current arrangement with Iowa starting first began in 1972, the election results have been thus.
First, for the Democrats.
| Year | Winner | Margin | Race Type | Predicted Winner |
| 1972 | Edmund Muskie | +13 | Contested | No |
| 1976 | Jimmy Carter | +15 | Contested | Yes |
| 1980 | Jimmy Carter | +29 | Uncontested | Yes |
| 1984 | Walter Mondale | +32 | Contested | Yes |
| 1988 | Dick Gebhardt | +4 | Contested | No |
| 1992 | Tom Harkin | +72 | Contested | No |
| 1996 | Bill Clinton | +97 | Uncontested | Yes |
| 2000 | Al Gore | +26 | Contested | Yes |
| 2004 | John Kerry | +6 | Contested | Yes |
| 2008 | Barack Obama | +8 | Contested | Yes |
| 2012 | Barack Obama | +96 | Uncontested | Yes |
At first glance, it looks like Iowa does pretty well. Of the 11 Iowa Caucuses held since 1972, 8 have accurately predicted the winner of the Democratic Nomination. That's a 72% success rate, significantly better than chance.
But I still argue that Iowa is not a good predictor of nomination winners. Why? Because not all Caucuses are the same. Let's start with the 1980 Iowa Caucus. Jimmy Carter wins the nomination by a large margin. But he's the sitting President in 1980 seeking re-election. Not since the Iowa caucus started has a sitting President or Vice President lost his party's nomination. The same is true for Clinton in 1996. He was the sitting President. These contests weren't really the same as the contests we're seeing this year in 2016. Thus, I argue that they should not count toward Iowa's record, since those races are not contested within the Party. This leaves 1972, 1976, 1984, 1988, 1992, 2000, 2004, and 2008 as the only Contested races and the only true tests of Iowa's predictive power.
That is 8 total contests and 5 where Iowa predicted the winner. That is 5/8, or a 63% success rate, almost within the margin of error of chance with such a low sample size. Essentially, you could get the same results by flipping a coin 8 times, easily. But what about the Republican matches?
| Year | Winner | Margin | Race Type | Predicted Winner |
| 1976 | Gerald Ford | +2 | Contested | Yes |
| 1980 | George H.W. Bush | +2 | Contested | No |
| 1984 | Ronald Reagan | +100 (unopposed) | Uncontested | Yes |
| 1988 | Bob Dole | +12 | Contested | No |
| 1992 | George H.W. Bush | +100 (unopposed) | Uncontested | Yes |
| 1996 | Bob Dole | +3 | Contested | Yes |
| 2000 | George W. Bush | +10 | Contested | Yes |
| 2004 | George W. Bush | +100 (unopposed) | Uncontested | Yes |
| 2008 | Mike Huckabee | +9 | Contested | No |
| 2012 | Rick Santorum | < 1 | Contested | No |
Vice Presidents have a slightly more difficult time gaining the nomination than President's do. They are almost always successful, but not always. Determining if a race is uncontested or contested in that situation is a bit more nuanced. The 1976 GOP Nomination saw Gerald Ford, Richard Nixon's Vice President and sitting President win by only 2 percentage points in Iowa. Ford did win his party's nomination, but barely eeked a win against Reagan. The results of that nomination process were close enough for me to judge it as Contested, even though a sitting President was seeking his own party's nomination. Additionally, in 1988, George H. W. Bush was the sitting Vice President, but initially struggled in the early part of the nomination process. Though he ended up obtaining the nomination easily, the early part of the contest was close enough to consider it Contested as well, especially since we're discussing the Iowa Caucus in particular.
There were three uncontested GOP nominations in Iowa's record: 1984, 1992, and 2004, all with popular sitting Presidents running unopposed. Therefore, these contests are not applicable to 2016. Out of 7 Contested Primaries since 1976, the Iowa Caucus has predicted the eventual GOP nominee accurately 3 times, a 43% success rate.
From the data, it appears that Iowa's claims of predictive power over the nomination process are overblown, at best. Dismal at worst.
