The DNC and their backers choosing the candidates are the main reason why the dems have struggled so much in the past two presidential elections because we ended up with candidates that were not very well liked(lessor of two evil situation) having the candidate chosen sooner and with less of a choice by the people will make this even worse because dnc will choose an even more out of touch person then they normally do. Having 7 months to introduce someone to a candidate is totally enough time just look at other countries and our own history of having fantastic candidates easily able to win because they were likeable