Retweets ≠ Endorsements. Unless they do. Sometimes a person retweets a message that he or she finds absurd/outrageous/despicable (pick any that apply) without intending to imply agreement. But sometimes, they do intend agreement. It depends. It sounds complicated, but it's usually easy to tell them apart in practice.
Today's blog post gives an example of both kinds of retweets. I think. The original Facebook post calling Muslims "the enemy" was shared by the "Richardson Tea Party Patriots." I assume that indicates their agreement. (They didn't condemn it.) I, in turn, am sharing what "Richardson Tea Party Patriots" posted. Not that I am endorsing it. (I condemn it. See how it's done?) I'm sharing it as a reminder that bigotry is real. It's here in Richardson in plain sight. We should all condemn it.