The Washington Post reports that the grand jury investigation of former FBI deputy director Andrew McCabe has been proceeding apace and now seems to be intensifying. As I understand it, McCabe is under investigation for misleading government officials about leaking.

The investigation was triggered by the Justice Department inspector general’s finding of wrongdoing by McCabe. The inspector general, Michael Horowitz (an Obama appointee), concluded in a detailed report that McCabe lied at least four times, three of them under oath, and that he approved a media disclosure to advance his personal interests over those of the Justice Department.

The grand jury activity, which includes hearing from witnesses, doesn’t mean McCabe will be charged with a crime. It seems clear, however, that prosecutors are taking the matter quite seriously.

As well they should. Robert Mueller’s team has prosecuted several people for not telling the truth to federal investigators. Based on the inspector general’s report, there is good reason to believe that McCabe committed the same offense. If he did, he should be prosecuted, just as those whom Mueller has scrutinized have been.

McCabe’s lawyer is crying foul, though, claiming that the investigation is politically motivated. This claim gains surface plausibility from President Trump’s tweets imploring the Justice Department to prosecute his enemies, including McCabe.

As noted, though, the investigation of McCabe is actually the byproduct of a Democrats’ investigation — that of Horowitz. Moreover, Jeff Sessions’ unwillingness to be cowed by Trump’s public call for partisanship in prosecutions should give fair-minded observers confidence that McCabe is not, and won’t become, the victim of a witch hunt.

I should also note that the case against McCabe may not be open and shut. For one thing, some of the evidence against him is based on clashing accounts by McCabe and James Comey about a conversation they had. Comey may not be telling the truth or the two might simply remember things differently.

Horowitz’s conclusions weigh heavily against McCabe, in my book. But whatever the prosecutor concludes about what the evidence shows, he will have to consider whether that evidence is strong enough to convict McCabe.

The key for now, though, is that the prosecutor seems to be digging hard into the evidence.