During his term he tried everything in his power to tie the knot between Naturals and Coordinators. However his term ended before Operation Spit Break and he was succeeded by the more aggressive Patrick Zala. They disagreed on various fundamental issues regarding Coordinators and Naturals; Zala viewed Coordinators as the new mankind and had no interest reverting to Naturals; Siegel doesn't see Coordinators as the next step in evolution and is very concerned regarding the sterility occurring in third-generation Coordinators.
Following Operation Spit Break, he was branded, along with all the other moderate members of the PLANTs, as traitor for betraying the PLANTs and giving information to the Earth Alliance. Clyne went into hiding, protected by loyal officers, but was found and killed with everyone around him.