You are not getting it.
In Colorado, ANY REGISTERED REPUBLICAN that shows up to their precinct can run for and be elected as precinct captain, state representative or alternate.
These are mom and pop grass roots republicans who, if they can convince their neighbors to vote for them, represent their precinct at the state convention.
I am getting it, you are not. The party made it intentionally complicated and difficult for normal people to vote because they did not want regular voters to choose. They even cancelled the customary straw poll because they knew Trump would probably win it. That is why only 60K out of 1+ million Colorado republicans actually voted. The Colorado GOP tweeted “We Did It! #NeverTrump” after the convention. They claimed the account was hacked, it turned out that was a lie. The fix was in and it was rigged against Trump, on purpose, by the GOPe hacks for Jeb! originally but they decided to give it to Ted Bush after Jeb! dropped out. There was nothing fair about it but that won’t stop Calgary Ted from bragging about winning rigged contests like that. The fact still remains that out of 26 contests decided by voters so far Cruz has won only 4. He does well in conventional and caucuses where it is easier for his GOPe buddies to rig it for him but Cruz has repeatedly demonstrated he does very poorly in voter decided elections. That is simply a fact.