By Daniel Burke, CNN Belief Blog Editor

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(CNN) - He's embraced a severely disfigured man, declined to judge gay priests, sought common ground with atheists and focused the world's attention on the poor and marginalized.

Yes, in the 18 months since his election as pontiff, Pope Francis has earned a reputation as one of the nicest guys on the planet.

According to a CNN poll, nearly 90% of American Catholics approve of the way he's running the church, and even atheists speak fondly of this Pope. 

But, if you watch him closely, you'll see a steely spine behind Francis's friendly smile. Just ask the Italian mafia.

In the video above, I explain 5 ways Pope Francis is tougher than you think.

By the way, be sure to check out our ongoing coverage of the Pope's trip to South Korea this week.