So were they aware of his affair? And if that was the reason they were going to prevent him from being the nominee, why not just leak the affair right away and nip the whole thing.
Another possibility for the trajectory of the Edwards campaign, of course, was not as the eventual nominee but as a power broker. As it was, Edwards was in the unfortunate position of hovering just below 15% in a lot of states in late January---so, if he had stayed in the race, he mainly would have played spoiler (hurting Clinton in the South and Obama elsewhere), while only picking up a few CD delegates here and there where he got lucky enough to break 15%. Certainly <100 delegates, total. If Edwards had done just a bit better (a more convincing second place in Iowa over Clinton, any organization at all in Nevada, and/or close to a tie with Clinton in SC), he might have had the chance to pick up a rather sizeable chunk of delegates, maybe on the order of a couple hundred, by breaking 15% in the South and maybe a few other places. Having a hefty number of delegates (though no more than 1/3 of the total superdelegate count), would make him a rather powerful player if the race dragged on until May.
So, if his campaign staff would still have liked Edwards playing kingmaker (as long as he didn't get made VP as a result), there was reason for them to wait on the sabotage front. Not to mention they probably weren't too eager to confront him / actually leak the story and effectively fire themselves by killing the campaign.
In any event, if there was any "sabotage plan," it couldn't have been in existence for much more than a week, if not just a few days...once Edwards lost Iowa, it was pretty clear he wasn't going to win the nomination---and the door was firmly closed after NH 5 days later.
