Trump is winning because he won plurality votes in 20 of 32 state primaries and caucuses. (NY was a majority.) That is a mathematical reality. It's not anti/pro Trump.
Look, Cruz is getting trashed, not by Trump but from millions of his American supporters, “the people”. Trump is winning support from the majority of the American people. On the R side this is not happening with Kasich or Cruz. This goes beyond this party line thing. Folks are crossing over, non-voters are again voting. And based on what we’ve all seen, this isn’t even debatable.