Social media, for all its benefits, has made it all too easy to find a group of people who will take your lowest impulses and hoist them on high, praising and burnishing them until they look like something fine and heroic. As you form relationships in the group and come to know and trust your new friends, and as the group members reward each other for holding fast to its ideals, the thing that used to make you feel a little uneasy about yourself slowly becomes your identity, the thing that fills you with pride.
This is how alt-right groups function. This is how terrorist groups function. This is how abusively rigid traditionalist groups function. And this is how dissenting groups function. Dissent comes to feel normal, even heroic. The subject matter in each group is different, but the psychological dynamics are the same.