With the recent Sanders endorsement of Clinton, I believe she has potential to sway the youth vote. Neither Clinton nor Trump are going to have strong appeal with young voters. But with Sanders backing Clinton, she will be able to piggyback on the success Sanders was having with the younger crowd.
Hillary Clinton should win the youth vote for a few reasons. First, she will have Bernie Sanders campaigning for her. Sanders is very popular among millennials. Second, younger people are against the type of racial prejudice that underlies the Trump campaign. Third, young people are more likely to vote Democrat to begin with.
No, Clinton won't lose young people when it comes time to vote because Sanders will impress upon his followers young and old that they need to go out there at election time and vote for her. Many young people would rather move out of the country than let Trump win, therefore, they will go out and vote for Clinton.
No, Clinton is not going to lose the youth vote. Many younger people are voting for Clinton, probably because they do not want to vote for Trump. They see Trump as rude and egotistical. There is a commercial where Trump insults and ridicules mentally disabled people, which is one reason why people might not vote for him.