I see no reason to trust it.

1. There's nothing on the site about who's behind it.
2. The list of "endorsers" is just a list. No URLs/links to their sites, no logos, no statements from any organizations or individuals. All data easily scraped.
3. You don't need to give your name, phone number, or email address to join a strike.
4. There's no contact information for the organization behind the website but they are demanding mine
5. The art submission page requires first name, last name, and email address. Again, why do they need my name but they won't reveal themselves?
6. The art submission page also has an option to "sign up for news and updates". This smells like a DNC fundraising ploy or something.