Why did Sheev Palpatine keep Mas Amedda in the Empire?

When the Empire was founded, Palpatine had an anti-alien stance. The Imperial army was so anti-alien that it took a Chiss with great skill and knowledge to become a Grand Admiral.During the fall of the Republic, Chancellor Palpatine had a Chagrin Vice Chancellor: Mas Amedda. After the Galactic Empire began, Amedda became a Grand Vizier. Why did he become in a position a power, and stay in that position for over twenty years, despite his status as an alien? via /r/StarWars http://ift.tt/2oFprZa