Voters already knew Hillary Clinton is a criminal. But for a few months, it appeared she could continue her quest for the presidency without the trouble of being charged for her misdeeds.

That may be history. The future may be something entirely different, as the result of a bombshell dropped by the FBI.

FBI Director James Comey seemed to have handed Clinton a pass -though far from a clean bill of political health – this summer. In July, he said an investigation of Clinton’s illegal use of private email servers while she was secretary of state revealed she had placed national secrets at risk.

But while what Clinton did was illegal, he would not recommend her for prosecution because there was no evidence she intended to do the wrong thing, Comey added.

That very excuse for letting Clinton off the hook may have come back to haunt both her and Comey.

On Friday, it was revealed the agency is reopening its investigation as a result of newly discovered emails. They may be relevant to the original probe, Comey himself informed some members of Congress.

Though the FBI has revealed little about the uncovered messages, it is known they were among thousands released by the WikiLeaks group of computer hackers. WikiLeaks has been posting messages it stole from various servers, related to Clinton’s work as secretary of state and her campaign for president.

All the FBI has confirmed is that the messages being looked into now relate to another investigation, of former Congressman Anthony Weiner. He is the estranged husband of Huma Abedin, one of Clinton’s closest advisers.

Millions of people who already have voted for Clinton or intend to do so have made that decision with great reluctance, simply because the candidate is, well, a liar. Public opinion polls indicate about two-thirds of potential voters do not believe she is trustworthy.

That is a terrible thing to believe about a person seeking an office in which trust is critical.

But the new FBI probe is an enormous problem for Clinton. Here is why: Comey already has admitted Clinton and her aides were not forthcoming when asked to turn over all emails relevant to the previous probe.

By definition, newly discovered emails that are relevant were not turned over to the FBI previously. That means someone withheld them.

That is obstruction of justice – a crime.

So between now and Nov. 8, voters have something else to consider: One cannot commit the crime of obstruction of justice without intending to do so.