Past Iowa winners:
1980 GHWB over Reagan
1984 Reagan unopposed
1988 Dole over GHWB
1992 GHWB unopposed
1996 Dole (26%) over Buchannan (23%)
2000 George Bush
2004 Bush unopposed
2008 Huckabee
2012 Santorum
2016 Cruz
As John Sununu said
Iowa picks Corn
NH picks presidents
not sure if it’s true, but it’s a fun quote