I think he has all that stuff as well? He's certainly got the money and he's got a big lever named "facebook" which gets his message infront of a substantial portion of the US voting public.
I am (anxiously) waiting for the "have you voted yet?" reminders Facebook has been using to get people to the polls in recent elections to turn into "have you voted for the Zuck yet?".
Can't do that. Zuck can't use FB resources or any form of support from FB (other than employees who volunteer outside work hours) for a political campaign. If he does he'll have to reimburse the fair value of services received from campaign funds.
But what if it were done on behalf of a super PAC that just happened to be in favor of his campaign?
It would be legal as long as there is no coordination with the campaign but I can imagine enterprise ending class actions against FB by minority shareholders if the Board violated their fiduciary duty to shareholders by involving FB in the campaign.