Joss Whedon wrangles a zillion celebrities for meta anti-Trump PSA

To mark the occasion of his new Super PAC, Save the Day, Joss Whedon enlisted about a zillion of his celebrity buddies to help him make a pro-voter registration / anti-Trump PSA.
Unlike most celebrity PSAs, this one involves all of the celebrities acknowledging the cliche of celebrity PSAs. They promise that if you go out and vote, Mark Ruffalo will do a nude scene in his next movie. They also point out that the most famous person gets to be on screen last (it's Robert Downey Jr., but I wou