Power
The power of clowns shouldn't be underestimated. Just ask Stephen King's Pennywise. Or don't. No, really—don't do that.
Laughter is a powerful, potent medicine. Take Patch Adams, for instance, who heals sick children with jokes and laughter. You can even join a Go!Clowns mission and spread the healing power of laughter to folks around the world who really could use a laugh.
There are also some pretty powerful people who hold political offices who many also consider clowns...but that's not quite the same thing.