Sebben impeached himself because he was not happy with his position as the 46.5 President of the United States of America.
Harvey Birdman: Attorney General is a 2018 half-hour special on [adult swim] that is a continuation of the animated series Harvey Birdman: Attorney at Law. The special, which reunites the original cast, will feature Phil Ken Sebben (voice of Stephen Colbert) becoming the 46 and a half President of the United States. In doing so, he takes the staff of Sebben & Sebben to the White House and promotes Harvey (voice of Gary Cole) to the office of Attorney General. As Phil continues to abuse his power, it is up to Harvey to stop him before people start to confuse reality with the plot of a ridiculous cartoon.