Probably why he's going to start hiring outside of tech hubs.
Regardless of location, Facebook is hiring from demographics that typically don't support Trump. Young, STEM-educated people skew left. If you want Trump supporters to even things out you're probably going to either: A) hire older devs from less traditional software dev backgrounds. B) Still pull from Young+STEM but filter out anyone whose social media indicates them as being left-ish.
I get the frequent recruiting emails from FB and (much less frequently) Google, but am really too afraid to pursue them.