The opposite scenario is equally consequential, though: What if it turns out these new emails have nothing to do with Clinton, yet Comey’s announcement hurts her chances in the election? “There obviously needs to be some sensitivity to the fact that an FBI investigation can be mischaracterized and abused in the context of an election,” Painter said.

In other words, Comey faces an impossible choice. If he refused to tell Congress, officials could claim he knowingly withheld information that was important to the American people. But in disclosing the investigation, he’s potentially shaping the outcome of the election; it’s unclear how the public will interpret the announcement, but the stock market has already taken a dive. As Benjamin Wittes argued on the website Lawfare, “Comey and the FBI are in a terrible position here, one in which they would be accused of playing politics whatever they ended up doing.”

Democrats are already saying Comey has acted irresponsibly. In a statement, Clinton’s campaign manager, John Podesta, argued that “the director owes it to the American people to immediately provide the full details of what he is now examining.” At least one group, which is associated with the anti-Trump Keep America Great PAC, announced that it filed a complaint about Comey with the Department of Justice. “It is an obvious attack from a lifelong Republican who used to serve in the Bush White House, just to undermine her campaign,” said Scott Dworkin, an adviser to the PAC, in an emailed statement from the group.

Comey’s letter to Congress revealed few details about the possible connection between the Weiner-Abedin emails and Clinton, nor about the potential classified nature of the messages. That’s part of what Democrats are calling him out on: With so little information available, Clinton’s political opponents are free to speculate about worst-case scenarios. As Donald Trump said on Friday, “This is bigger than Watergate.”

The former Department of Justice spokesman Matt Miller argued on Twitter that Comey has violated the precedents of his office by commenting publicly on the Clinton email investigation in the past. “Today’s disclosure might be [the] worst abuse yet,” he wrote. “Why? Because voters have no way to interpret FBI/DOJ activity in a neutral way. Who is the target of an investigation? What conduct?”

Even if Democrats wanted to punish Comey for his actions after the election, their options would be somewhat limited. The president nominates the FBI director, who is then confirmed by the Senate to a 10-year term.* If the Clinton administration wanted to get rid of Comey directly, it theoretically could. It’s happened before, although it’s rare: Bill Clinton dismissed FBI Director William Sessions on the grounds that he had improperly used an FBI plane for personal purposes. But in this case, it would be difficult to prove Comey acted irresponsibly; while it’s not clear that the president has to have “cause” to fire an FBI director, a politically motivated dismissal could provoke backlash. Congress could also impeach Comey, but that would be an arduous process.