They are just so F^&king arrogant they think they can get away with this. They are probably planning/hoping they can smother the news but the joke is on them because the Rasmussen poll will smother EVERYTHING else until Tuesday.
As you remarked, there may be political / popularity / polling ramifications, and if a drop there is how one meaures "getting away with it," you may be right. That depends on the contest and how effective the press is at transmogrifying the appearance of conflict or impropriety into a GOP-lead partisan witchhunt.
On the legal side though, nothing will happen. FBI will report "here are the facts," with no opinion and likely no citation to statute. DOJ will decline to prosecute. There will be outcry that will die down. The press will classify any outcry as GOP-lead partisan trash.