Romney had the primaries to himself by the end of March in 2012. Santorum quit and that was it.
So that voting dropped off in April is no surprise as Romney had it wrapped up.
Neat stats.
Reality is that there have only been four primaries in April, and Cruz won 3 of them in CO (no actual votes cast), WI (Cruz win), Wyoming (Cruz win tiny state), and New York (Trump win).
So your post makes no sense, but thanks for sharing it as you circle the drain of credibility.
I didn't realize that Trump was 2.3 million votes ahead of Cruz. In the real world, we call that a landslide, and Cruz and Kasich would have already dropped out as well if their big money donors weren't desperate to get Hillary in the White House.