Here’s where it can get confusing: When Insecure Bullies act like Xenophobic Bullies, it might not be fear so much as their noticing something physically obvious that singles you out, therefore making you an easier target. A Troll may single you out because of your reaction. A Flunky Bully may not have anything against you, but attack you anyhow, just because the Xenophobic Bullies are, and Flunkies don’t want to be left out or worse—made into targets. But we’ll get to those other kinds of bullies later.... The important thing is that you can get an idea of motivation, which can lead appropriate methods of dealing with the bullying behavior.
The good news about Xenophobic Bullies is that you have an above-average chance of reasoning with them. Well, if these bullies don’t also have too many other motivations, or the tendency to be violent, you have a chance. If you do try to reason with them, do it one-on-one, and make it seem like the bully (or bullies) would be generous and mature to call a truce. Or focus on how only cool people learn about other cultures, but the bully seems different and smarter than the others, so you’d be willing to share some stories, resources, and maybe eventually invite her/him over for dinner to meet your family.
Think of what famous people are popular among your classmates, and share whatever trait (i.e. race, religion, ethnicity) for which you're being bullied. Then mention it to people, like "Hey, this musician, movie star and NFL star are all (fill-in-the-blank), like I am." If others know, especially the fans of those celebs, it's like invisible backup.
You can even periodically wear a t-shirt or button referencing one of those celebrities, so that it registers in kids’ minds that picking on you is like picking on their heroes.