There is a group called “Writers Resist Trump” (a public group on Facebook ). You have to join the group (which requires approval) to get their posts.
There is also a Writers Resist or Write Our Democracy group.
The groups held a protest in Lafayette Park outside the White House early Saturday night. I did not hear about the protest until this morning. The group seems to be a bit tightly knit. Here is the story on WJLA.
It’s significant that writers as a group see Trump’s authoritarianism as a long term existential threat.