Here's a fun project: this site lists all the superdelegates in the Democratic primary, by state and whether or not they've committed to backing Clinton. Those with Twitter or Facebook pages have links given, but mostly they are political officials who won't be hard to find.
It's probably worth your time to ping the ones from your state, and tell them that you won't thank them for backing Clinton if Sanders wins the local primary. Whatever we can do to undermine her last bastion of support is worth doing, as she is by far the worst choice in this election. We cannot afford to turn national security over to someone for whom the lives of its defenders are so small a concern next to her own convenience. Nor is her relationship to the truth, in general, apparently a wholesome one.