False argument. Constitution and party rules allow states to determine the selection process. Never been direct democracy. To this day, delegates/electors select the candidates/POTUS/VP. And Trump has benefited greatly from the “corrupt” rules, and he’s not whined about those caucus states / territories he’s won or in which he’s done well. Fake, selective outrage by a bully.
In 1968 the DNC gave the nomination to Hubert Humphrey even though he didn't win any primaries, and he lost the general election. That may have been a special situation because of the RFK assassination, but four years later Humphrey got a fraction of a percent more primary votes than George McGovern. The party gave the nomination to McGovern and lost big time.
Nowadays you could compare the party conventions to the electoral college. It's not an exact or perfect parallel, but the convention or electoral college can do whatever it wants, but it will pay the price if it doesn't pay attention to electoral results.
So vote for Shrillary & stop bitching.