The same thing is happening within the Democratic Party currently.   It just is being done in a far more subtle and respectable way, that does not generate as much headlines.

The Democratic Party leadership wants Bernie Sanders defeated just as strongly.   They, and all of the corporations and special interests that fund them, want Hillary to be their candidate.   They, just like the Republicans, want a President that they can control, and who will follow their agenda.

Neither party has any interest at all in what the actual American people themselves want.   Or doing what is best for them.  Both have sold out to corporations and special interests, and serving their needs.  

The race that the two parties want is Clinton vs Rubio.  And they will do all that they can to make sure that is the choice that the American people will have in November:  two candidates that will be beholding to their parties, and not the American people.