Yeah...Iowa hinted the “being presidential matters” by electing Huckabee, and others, who went on to lose the nomination.
Facts are pesky things. You might want to look into them. Iowa has nominated the last five Dem candidates in a row, and has only one "miss" since '96 - in '08, they chose Huckabee, as you noted. In '12, Mitt tied Santorum, 25 pct each. That's not exactly a "miss". In '00, they nominated W. In '04, W was unopposed. So, Iowa is 8 for 9 by my count. Nice try though.