The flaw in your logic is that other groups managed to vote. The ugly truth is that young people who have not been part of the process did not figure out how the process worked. I know because I did my best as a grassroots dem to help them but the thing is, grassroots people can only do so much. If you want to vote or want a specific candidate you have to reach out and find out the deadlines and all the other stuff. If you think the deadlines are too early and the process unfair, then you work to change it. BTW, the long lines thing is that many people showed up for the first time to things like precinct caucuses. That means grassroots people like me scrambled to find larger venues and worked for hours to get everyone signed in so they could have a voice. Yes, the lines were tough for all of us but we in the grassroots have no idea how big a crowd is going to be, we have to guess and then it's volunteers like me running the caucuses so yeah, it's not a perfect process. In fact, it's democracy, which is rather messy.