How much are we willing to do to end political corruption?

And so the stain keeps spreading.

Last year, federal prosecutors began looking at the way judges are selected in Suffolk. And, more recently, into allegations that James Burke, formerly the top uniformed officer in the police department, beat a suspect and then pressured subordinates to cover it up.

And now comes word, via a Newsday report from Robert E. Kessler, that the federal investigators are reaching into the Suffolk district attorney’s office. According to the report, a grand jury is investigating whether Christopher McPartland — District Attorney Thomas Spota’s top corruption investigator — participated in meetings with county law enforcement officials, encouraging them to lie about Burke’s actions in the alleged assault of suspect Christopher Loeb.

So many investigations — and into three institutions that are supposed to act as checks on each other, even as they fulfill government’s most essential role, which is providing for the safety, health and welfare of Suffolk residents.

Judges.

Police.

And a prosecutor.

None works without the others; and yet, as the Eastern District’s investigation continues, all are now caught up in a corruption investigation.

Could this be the worst scandal in Suffolk’s history? Where the alleged deeds of individuals even now taint the public’s perception of Suffolk’s system of law and order?

Yes, some political and other insiders will — and indeed, last week, did — say Suffolk may have been operating this way for a long, long time. But there is a difference between suspected corruption and being forced to see such allegations marched, so loud and so brazenly, out and into the public eye.

“Could this be the dirtiest cop in America?” a piece in Newsweek on Monday asked of Burke, who has pleaded not guilty. The Washington Times, in picking up Newsday’s report on Burke’s payout for unused sick and vacation pay, went with the headline “Ex-police chief in N.Y. facing federal charges to receive $430K payout.”

Yes, how Suffolk works is dropping jaws these days.

And, somewhere down the line, Nassau could end up dropping a few jaws, too, as separate ongoing federal investigations into alleged bribery and other wrongdoings by a vendor whose private loans were guaranteed by the Town of Oyster Bay, and a probe into whether county contracts were steered toward political contributors, continue.

But what about us? How is it that so much could go on for so long? And — like efforts to curb vendor donations to elected officials in Nassau — why is it that efforts at reform go nowhere?

And why do so many of Long Island’s elected officials choose to be bystanders?

Is corruption so normalized on Long Island that residents accept it? Or that elected officials are blind to the need to address it? The federal investigations are as much about us as about the individuals and institutions involved.

It remains to be seen what more federal investigators turn up in their ongoing corruption probe. And ultimately, as for Burke, how well they make their cases.

Still, it’s not too early to ask:

What can we do, and what are we willing to do to restore the public’s shaken trust?