The GOP candidacy will start for real, with Iowa.
It will either end up contested in that race, and will turn into a real race.
Or if Trump manages to win in Iowa, we will quickly see the GOP consolidate around him.
But at very least we need to see what happens there, before declaring anything.
The GOPe will not consolidate behind him any more than they did in Mississippi and Alaska. The GOPe would rather lose than see an outsider become President.
The first 4 states have to vote before we even know who's in the race, much less who's going to win it.
Only one candidate needs IA and that is Cruz. It doesn't move the needle on anyone else at all. It will not change the mind of a single NH voter or a SC voter, period.