Zuckerberg couldn't run as anything but a democrat either. Cambridge Analytica and the like ensured that, but his beliefs (as far as he has shown any) are leaning democrat with libertarian tendencies at best. His lack of moral spine is compatible with both parties (not equating said parties to be clear).
2) Bloomberg ran as a democrat
Imagine a world where you get your news from Fox News and then go to a conservative controlled facebook. He would be unstoppable.