What's up with the MAGA hats in Brisbane lately?

I don't understand how American politics are so relevant to some Australians. Yesterday I served a girl who looked around 10-12 years old wearing a, 'Make America Great Again' hat. It's not the first time I've seen someone here wearing that hat, but the age of that kid shocked me.

Also the store is inside. And she had an Australian accent. Kids shouldn't be brought into politics.

Edit: spelling.