Many times spammers don't just post new answers (or questions) with their spam but also edit existing posts to insert their spam. Usually two high rep members will notice the spam and reject the suggested edit, but sometimes spam slips through; here is one recent example I bumped into earlier.
I understand it was an honest mistake made by two approvers and of course I rolled back the edit, but it got me thinking: what if I wouldn't have noticed? Evil spam can claw its way into our decent community like that.
The spammer account was quickly nuked, but unless one will notice edits made by that account they could be left alive for good.
My suggestion is that when an account gets nuked due to spam (guess manually by a moderator?) all edits suggested or made by that account will be automatically rolled back to the previous version.