There’s a bug going around, I know, so maybe I shouldn’t make too much of the way Ald. Edward M. Burke’s voice caught as he answered to the charges against him Thursday in federal court before U.S. Magistrate Sheila Finnegan.

Still, Burke’s tentative “yes, your honor” and “no, your honor” in response to Finnegan’s questions did not fit with the confident voice of the prideful Finance Committee chairman who Chicagoans have come to know as the primary force behind the City Council over several decades.

It was the defiant Burke who entered the Dirksen Federal Building with his head held high beneath his fedora. Inside the courtroom, his demeanor was calm and unruffled as he waited in the front row for his case to be called, resplendent as usual in a gray pinstripe suit and pink necktie with a red-trimmed white hankie protruding flamboyantly from his breast pocket.

But the voice betrayed him — nervous, squeaky. It was the voice of a man who knows he’s facing serious legal trouble.

Maybe that’s because Burke knows there’s another bug in play here, not the respiratory kind that possibly accounted for him finally clearing his throat, but the wiretap kind — the kind of bug that lays bare secrets.

The 37-page criminal complaint released Thursday against Burke accuses him of trying to extort the owners of a fast-food restaurant in his ward by holding up a remodeling project while he squeezed them to shift their real estate tax work to his law firm.

The restaurant is part of a large chain of Burger Kings owned by Tri City Foods Inc., the allegations quite clear that Burke wanted to have it his way at all the company’s Chicago area Burger King locations.

Part of the purported evidence comes from a wiretap on Burke’s cell phone.

One of the intriguing twists in the case is that the court filing makes clear the wiretap was already in place when investigators came across the alleged Burger King shakedown in 2017.

That means investigators obtained the wiretap on the basis of suspicion of some other wrongdoing involving Burke. The federal complaint does not indicate what that investigation might have involved or whether it bore fruit, but prosecutors emphasized in court that the probe is ongoing.

Burke’s defense will be that he was pursuing legitimate concerns about whether the project was properly permitted and that there was never any explicit demand for a quid pro quo, also that there’s nothing on those recordings that proves otherwise.

And I’d say there’s just enough wiggle room in what I read that he could take that argument to a jury. It will help him that, in the end, the restaurant received its permits and he never got the legal business.

But if this case ever does get to a jury, that defense could be a roll of the dice for Burke, especially if any of his cohorts in the alleged extortion roll over on him.

For now, though, I wouldn’t expect Burke to give up easily — or withdraw from his aldermanic race as some have predicted. His power flows first from being 14th Ward alderman, and he will need to cling to that power as long as possible while he fights the charges. On the other hand, the pressure to step aside as Finance chairman may be more than he can withstand.

The shakedown scheme of which Burke is accused is exactly the sort of thing of which he has long been suspected as an explanation for that long list of corporate clients hiring his small firm of Klafter & Burke to appeal its property taxes.

The question has always been whether he and other politicians explicitly use their political muscle to solicit business or whether they are careful in keeping their official duties separate.

In the final analysis, there’s not much difference except that the former is more likely to get somebody indicted.

That bug Burke has could prove contagious to several mayoral candidates who in the past have sought his favor but now are eager to distance themselves.

They must be concerned he will sneeze.