An ongoing investigation by the highly respected U.S. attorney for Southern New York, Preet Bharara, apparently is targeting the top levels at City Hall, and there are reasons to expect that if a case is brought, it will be under the leadership Jeff Sessions, President-Elect Trump’s designee for attorney general.

Michael Goodman of the New York Post reports on some serious clouds on the leftist mayor’s horizon, as the mayor desperately tries to hide emails that have been subpoenaed:

Mayor de Blasio, calling questions about his shady dealings with political consultants and lobbyists a “distraction,” says from now on. he will release all his e-mail exchanges with them — even as he fights to keep his past exchanges secret.

“New ground rules now,” he said breezily on NY1, which, along with The Post, is suing him to get those past exchanges.

You’d have to have been born yesterday to not see through his ruse. There must be something so damaging in those existing e-mails that de Blasio is willing to make a fool of himself to hide it. The public would be foolish to let him succeed.

By public, I include Manhattan US attorney Preet Bharara.

He can end this charade and answer the explosive question of whether the mayor sold government favors to the lobbyists’ clients and other donors in exchange for campaign contributions and other things of value.

The time for Bharara’s answer is short because his investigation has been long. It is nearly 2 years old, and its focus on fund-raising reportedly involves some events that happened before the mayor took office on Jan. 1, 2014.

Indeed, a case must be brought before de Blasio’s election is too close.  It looks as though a lot of evidence is on hand, so if there is a case, we could see something official next year.

The sense that Bharara’s final shoe is about to drop is especially keen because he filed related corruption charges against businessmen, police officers, a hedge-fund manager and the head of the correction officers’ union.

And with subpoenas served months ago on City Hall, de Blasio deputies, some consultants and donors, it is clear that Bharara is aiming at a substantial target.

That could be why the prosecutor recently agreed after an unusual meeting with President-elect Trump to stay on past the end of the Obama administration.

That’s what has to worry de Blasio.

Once integrity is restored to the leadership of the Department of Justice, corrupt politicians of all political stripes should be held accountable.  But with the DoJ in the hands of highly political A.G.s Eric Holder and Loretta Lynch for eight long years, I suspect that some Democrats may have gotten sloppy.