In The Future Will The Democrats Have To Shift To The Left?

I thought to myself that it is very plausible that the establishment will have their way with this election. Older voters are very reliable, and will vote for anything that has the last name Clinton attached to it. However, the establishment Democrats are banking on a older generation that is shrinking. The millennial generation will be here for many years to come. Their generation of politics has been decisively left, as opposed to those who grew under the warmth of Reagan and Clinton. How likely is it that the Democrats are going to have internal ideologue struggles similar to those of the Republican party?