Ozai. He controlled the complete Fire Nation.

Ozai: The entire Fire Nation and most of the Earth Kingdom

Amon: Republic City

Jianzhu: Most of the Earth Kingdom

Long Feng: Ba Sing Se

Ozai wins

I'd say either Long Feng or Ozai have the most political power

I'd pick ozai overall cause he runs the entire fire nation as well as earth kingdom territories AKA the fire nation colonies the earth kingdom like for example .Omashu aka new ozai. he and the fire nation conquer ba sing se and take control from Long Feng