What does Donald Trump's victory in the 2016 presidential election suggest about the power political parties have over their candidates and fellow party members?

Party leaders are limited in their abilities to choose and control their nominees.

Explanation:

Donald Trump winning the 2016 general election in the United States despite not having any major endorsement or support from the various major party leaders has  made it obvious that Party leaders are no longer very powerful in their abilities to choose, influence and control their nominees.

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