Does knowing about the personal history of an artist change how you view the art? How much should it?

I was thinking about writers, and books I've read where I learned more about them after the reading. Several of the books I've sort of reinterperted based on this new knowledge of their background, and it was making me think, "Is that the way to view a work?"

It's certainly a way to view one.

If the art isn't political in itself, like say, and fantasy book, does knowing the author is a strident Republican, or having a Mormon background like Orson Scott Card, cause you to taint the reading with bias, or allow you to see the work in a properly contextualized way?

And as you get away from say, books and films, how much then does it matter? How much does the painting change knowing the painter?

If I knew the personal details of the artist before reading the book, does it alter my reading of it in a totally unintended way?