A Kohen takes precedence over a Levi, a Levi [takes precedence] over a Yisrael, a Yisrael [takes precedence] over a mamzer, a mamzer [takes precedence] over a Nesinite, a Nesinite [takes precedence] over a convert, and a convert [takes precedence] over a freed slave.  When is this? When they are all equal. But if the mamzer is a Torah scholar and the Kohen Gadol is ignorant —- the mamzer who is a Torah scholar takes precedence over the Kohen Gadol who is ignorant.