Update: Little Mix won this round. Click here to vote for their Mixers in the Semi-Finals!

There's something to be said for the camaraderie that comes with being part of a devoted fanbase. That's why we're using this year's March Madness to find out which celeb has the greatest fanbase of all. (Tough, we know.) For round one, we put Little Mix's Mixers against Fifth Harmony's Harmonizers. Gather 'round, everyone. Which group has the better fanbase?

Little Mix's Mixers are crazy intense and totally obsessed with the girls, and when you consider the origins of the group itself, it isn't too surprising. If it weren't for their fans, Little Mix would not have won the X Factor UK. Sure, some cosmic force may have eventually brought the four of them together, but like, probably not. And let's be real -- we'd rather not consider the possibility of a Little Mix-less universe, anyway.

Fifth Harmony's origin story is similar to Little Mix's -- they, too, started out on the X Factor, and while they didn't win the competition, they had a built-in fanbase of Harmonizers by the time the season was finished. And isn't that kind of like winning, anyway? Fans of the group get hashtags trending whenever something happens to one of the girls -- be it a birthday or something serious and solemn. One thing we really love about Harmonizers is that they've got the girls' backs no matter what.

Which fanbase deserves the glory of being declared the ultimate example of mass devotion? You can vote once per hour until the polls close at 3PM ET on March 17. Choose wisely.

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