Apparently the dramatic jailing was prompted by Sarkozy's refusal to respond to a court summons; such arrogance doesn't tend to go down well, especially in France which has a centuries-old tradition of punishing its former rulers for various misdeeds. If the suitcases full of cash were real, it's a serious violation of EU money laundering laws, before the alleged origins (Libya) are even taken into account.
Given that much of the money was spent renting enormous football (soccer) and other stadiums for rambunctious rallies...perhaps Sarko has some pseudo-narcissism going on?
Not to say a comeback from such scandal is impossible; erstwhile octogenarian honcho of Italy Silvio Berlusconi - NA perhaps? - has form, despite looking like a plastic action figure of himself in his 2018 reincarnation: