That is a superb explanation of how it is done by the grass roots.
So the senator will leap frog from 8.3% to over 22.3% for the real-estate mogul in Iowa! OK!! This will be worth watching.
You say the Cruz percentage right now in Iowa is 8.3%. If that is accurate, it is the result of a telephone call to a limited number of voters. Also, in these phone calls, Trump has 22.3% if your numbers are accurate there. This exact type of poll had Cruz losing to the Lt. Gov., for the US senate seat, even the day before the election. The next day, Cruz won by a considerable margin.
So, a win depends on the amount of effort exerted by the candidate to reach the individual voter at the right times before the actual voting day. Of course, if you have a lousy candidate, nothing will work. The candidate has to be a viable candidate plus put in the organization to cover all the bases.