From her sitcom 30 Rock and her time at SNL I would say her political engagement is minor, mostly due to the format of those shows. They often make fun of right leaning people/beliefs but it's not very deep. The comedy style is silly and absurd.

I'm a pretty big fan of Mark Twain and Tina Fey. I like the self deprecating misdirection of the joke. I don't necessarily agree with the criticism of Mark Twain but at the same time if someone wrote a satirical n***** Jim character today it would not be well received. It's also interesting that Fey made that comment in 2010 and roughly 10 years later several black face scenes from her show 30 Rock have been pulled from streaming services. Some of those scenes I think most people would agree were in bad taste.