Both Justin Bieber's Beliebers and 5 Seconds of Summer's 5SOS Fam emerged victorious in Round 1 of March Madness, with the Beliebers beating out One Direction's Directioners by a (perfectly groomed) hair and the 5SOS Fam edging out the Vamps' Vamps Family by over 72% of votes. Now, the Beliebers and 5SOS Fam are facing off against each other in round 2! Who should win?

If we could only use one word to describe Justin Bieber's fans it would undoubtedly be "hardcore." Beliebers will fight to the death for anything involving their beloved idol, whether it's staunchly defending him against haters or just trying to get the closest look at the Biebs IRL. Of course, it's no surprise that Beliebers are such a die-hard group -- JB gives them something to belieb in, and you better belieb your Beliebin' butt that he does as much for his fans that they do for him. We love that their love is so mutual!

5 Seconds of Summer's 5SOS Fam is one seriously kickass group of people. While some members have been fans since the guys' fetus YouTube days and others have discovered the band later, the most important thing about the 5SOS Fam is that they show the boys their unwavering support and obsess about every possible aspect of the band -- two of the most crucial aspects of anything fandom, if you ask us. Plus, we love to think of the collective unit as an actual "family" -- after all, where else can you go to dissect everything 5SOS ever?

Who is most deserving of the Best Fanbase title? You can vote for Beliebers or 5SOS Fam once per hour until the poll closes on Tuesday, March 24 at 3 PM ET. The winner of this round will move onto round 3 and be one step closer to getting crowned Best Fanbase!

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