There is no excuse for corruption. However, everyone in all countries should ask themselves whether or not most of the representatives in their congress/parliament would, if investigated, be found guilty of the same sort of corruption. Power corrupts.
If you read up on this story, you'd find out it's not run off the mill corruption. Sarkozy actually conspired with a foreign state – in particular with someone who directed a terror attack that killed 50 french citizens (!) – to fund his campaign.
Relatively few politicians get their campaigns funded by hostile states, although it increasingly becomes more common. And while corruption is multifaceted this is clearly one of the graver violations. Let's hope all of them end up prosecuted. People were shot for less.