Every Presidential election cycle, it seems the GOP puts out a field that comes up weaker than the last one.
The loser candidates they pick every election cycle are just go-along-to-get-along RINO types who won't rock the boat. The monied interests that control the GOP establishment believe that they can get by with just enough foolish Republican voters to allow them to thumb their noses at any and all conservative dissidents.
Considering the average low-information Republican voter, they're probably right.