The Young Turks network is taking a survey as explained in the YouTube Video. Here is the explanation of the video.
Are you dissatisfied with Hillary Clinton as the presumptive democratic nominee for President in 2016? Are you hoping for a more progressive candidate? We want to know who you want, email us your choice of candidate at firstname.lastname@example.org once we receive your choices we will publish petitions for your candidates at http://www.tytnetwork.com/petitions. We’ll leave your petitions up on our website until October 1st, at that point any candidate who has reached 1000 signatures on their petition we believe should be taken seriously as a legitimate progressive challenger to Hillary Clinton, we will leave those names up on our website indefinitely to see how many signatures those petitions get. Email your choice for a progressive challenger to Hillary Clinton at email@example.com
I think that if your candidate is already on the list, you just have to go to the website above and cast your vote (sign the petition).