Simple, 60-70K people who voted for Democrats last time signed up as new GOP on the day of voting so as to pump up Rubio da Rino and eventually force a brokered convention where the GOPe can install whom they want.
Dont be fooled. Cruz is no outsider. He has neocons backing him...like co founder of chertoff group. Chad sweet. Chertoff advised romney
The real question is can Cruz replicate his Iowa organization in the other 49 states? A lot of candidates do well in Iowa because they devote the time/resources, but then find they aren’t well position everywhere else.
All this analysis and hype over Cruz getting ONE delegate more than Trump. This is why politics is so stupid.