I remember this because I recently read the transcript.
Sessions Confirmation Hearing - January 10, 2017
Sessions told Grassley he would recuse from Hillary e-mail and Clinton Foundation cases because he'd said things that would be taken as showing him to be biased.
With regard to cases involving the Trump campaign, Durbin asked a hypothetical, and Sessions said he didn't think he would have to recuse if the campaign came under investigation, never having said anything about it, but he would consult with the conflict experts at DoJ and would follow the regulations.
Franken's Russia question is a smokescreen masking the real reasons for recusal. Both recusals would have happened whether the Franken/Russia fiction (that Sessions lied in the hearing, therefore Sessions might actually be involved with Russia) surfaced, or not.
The recusal regulation prohibits taking cases where the prosecutor has a FRIENDLY relationship with the defendant.
This right here would be sufficient reason to remove Sessions. It explains why Sessions is not doing anything whatsoever to the DNC, because he might be "taken as biased."
It's completely retarded and means he is useless as AG, because what is needed is someone who will go after the Dems.