The explanation is more complicated than you can absorb but the Comey scenario was very much a matter of Comey coming in line with the wishes of his Dem Overlords. BUT he was in serious trouble because he outgamed himself. He let Hillary off the hook with the promise that if any new evidence came up he would jump on it. Then later, he was tipped off by the NY field office that McCabe had copies of documents and direct knowledge of additional Hillary emails that had been uncovered as part of the Weiner prosecution/Huma's emails. That put Comey in a very difficult situation- wherein he had promised that he would act upon and make it known if any new information was uncovered but his deputy director McCabe was sitting two offices down with the new emails and material from Huma/Weiners phones/computers. So he reacted by immediately outing it. At that point, Comey was in survival mode- not Dem or Republican mode. It was then all about Comey.
Yeh, you don't get it. Don't bother to tell me. Others do though.