Background
During the election, Attorney General Loretta Lynch met with Bill Clinton. Clinton had been Lynch's employer, so from one view, it was understandable. However, at that time, Lynch was also overseeing an investigation into Hillary Clinton's use of a private email server. It is of course extremely improper for a prosecutor to have a relationship with the person under investigation or her spouse. Lynch and Clinton were probably close enough that she should have recused herself from the investigation prior to that. The meeting was the last straw, clearly improper.
The larger problem was that if Lynch had a conflict of interest for that reason, so did most of the other people who could have taken over for her. Further, anyone from the Barack Obama administration who exonerated Clinton would look like they were playing favorites for political reasons.
James Comey
Someone had a clever idea. If instead of a Democrat, they had a Republican exonerate Clinton, it would look better. Where to find a Republican in the Obama administration? FBI Director James Comey. So they had Comey give the report that he was giving them to the public. However, this is generally considered inappropriate behavior by the FBI. They are supposed to release such reports to the prosecutors, who then make the final charge or not determination. So Comey's exoneration of Clinton politicized the FBI.
Comey tried to make up for that by also including derogatory information from the investigation. But Democrats and some Republicans pointed out that that was also inappropriate. Unless used for prosecution, it is inappropriate to use private information from an investigation to attack the person under investigation.
It is arguable that the exoneration and/or the derogatory information was intended to influence the election, which is illegal for most federal employees (including the Director of the FBI) under the Hatch Act. Comey's inclusion of both may have been partly intended to mute this by taking both sides of the question.
Others argue that this is a bit of a reach. That Comey's job required him to produce such a report, and it was within the president's discretion to have Comey deliver it publicly.
Congress
Congress called Comey in for hearings. Democrats and Republicans could ask why he did these things. During the hearings, someone asked Comey if the investigation was ongoing and Comey said that it was not. The followup question asked if Comey would let them know if that changed. He said that he would.
In October, it changed when the FBI found additional information related to Clinton's emails in an unrelated investigation into the sexual habits and communications with minors of Anthony Weiner. Weiner shared use of a laptop with Huma Abedin, a personal assistant to Clinton (her body woman). As part of the Clinton investigation, Abedin had been required to turn over all devices on which she received email. She missed a laptop in Weiner's possession, either through negligence or intentionally.
In any case, the FBI launched an investigation. Since Comey had told Congress that he would notify them if the investigation went active, he did so. Democrats argued that he should not have done so, since it was within the last month of the election and regulations say not to do so. However, they did not point out that restriction back when Comey testified before Congress without such a restriction.
The FBI deliberately went through the laptop as quickly as they could and determined that they had already seen all the emails available on the laptop. So Comey announced that they were closing the investigation. Again. Of course, this also happened in the last month of the election.
Both those events could be argued to violate the Hatch Act. Again. In both cases, Comey could argue that he was just doing his job. Again.
Democrats vs. Republicans
Republicans were unhappy with
- Comey advised against prosecuting Clinton.
- Comey announced that the investigation was closed.
- Comey announced that the investigation was closed again.
Democrats were unhappy with
- Comey released a scathing denouncement of Clinton's security practices.
- Comey reopened the investigation.
- Comey told Congress that he reopened the investigation.
So neither side was happy.
During the campaign, this somewhat balanced. As distance from the campaign has increased, there has been less partisan support for Comey's decisions. This makes it easier to criticize him. On a non-partisan basis, every decision except reopening the investigation is subject to criticism.
- The FBI should not be publicly advising on whether people should be prosecuted.
- The FBI should not release information from an investigation directly to the public.
- The FBI should not say publicly if an investigation is closed or reopened.
- The FBI should not promise to keep Congress updated on the state of an investigation.
The net impact of each of these decisions has been to politicize the FBI. Some people, regardless of their personal politics, think that that is a bad thing in and of itself. And partisans can easily point to decisions of his with which they disagreed.