The American Primary Election system is such that special attention is given to early voting states such as Iowa, South Carolina, New Hampshire, and possibly Florida.
By the time many states have their turn to vote in a Primary... their political party may have already have a candidate selected.
No offense to Iowa, but being a resident of that state should not give you superior voting rights.
I suggest making "Primary Day" the first Tuesday in May... which, is 6 months prior to the date of the General Election.