Hi Goddess,
It's actually fairly important, but not always in the way you're thinking. Sure, a high number of followers is great, but a low number isn't so much a big deal. Publishers can help with that, and a good story does help.
However, if an agent or editor sees you're on social media harassing people, demanding Trump build the wall, and that Newtown never happened — it could (read "is") a problem.
Reality is that most creative arts industries are predominantly liberal. Especially nowadays editors either want their authors political or apolitical. Also consider publishers and their imprints carefully curate their brand. If you want to write for Regnery Publishing — a conservative publisher — blasting pro-Hillary and anti-conservative politics on Twitter won't help your case at acquisitions.
Tor is predominately liberal and you'll notice their books lean that way politically.
Also, you'll run into editors and agents who don't want to be associated with someone who preaches the Flying Spaghetti Monster is going to destroy America and eat all children.
Just my $.02.