State Auditor Diana DiZoglio has run into a powerful buzz saw in the form of Attorney General Andrea Campbell and Senate President Karen Spilka and is now just wasting time and money in a doomed attempt to audit the Legislature.

Even if the auditor goes forward and gets a ballot question passed giving her authority to look at lawmakers’ books, it’s highly likely it will be ruled unconstitutional by the courts because of the separation of powers’ principle. It’s over.

Campbell, in a letter to DiZoglio on Friday, concluded that the auditor has no “legal authority” to audit the Legislature without their consent – which Spilka and House Speaker Ron Mariano immediately jumped on to buttress their case.

The Democratic AG also warned that if the ballot measure passes, “we may need to consider whether, and the extent to which, constitutional limitations affect how the law would apply.”

Boom. Those words should make DiZoglio pause before she continues her quixotic bid to go after Spilka and Mariano. It might all be a waste.

Campbell’s surprise ruling on Friday dealt a huge victory to the embattled and entitled Legislature – which is the least transparent in the nation.

“I am heartened that the Attorney General and her highly experienced legal team reached this conclusion – the position we have argued for months – based on the law, the facts and the historical record,” a giddy Spilka wrote to senators. “The Attorney General’s findings are crystal clear; the Auditor’s proposed audit has no basis in law and shall not proceed.”

DiZoglio said in a statement she respects Campbell’s “right to her opinion, and to defend the position of legislative leaders” but she vowed to continue pushing the ballot question.

“However, a question of statutory interpretation on a matter of such importance to taxpayers, is best answered by the courts, not the executive department of government,” she said. “Massachusetts has one of the most opaque Legislatures in the nation and this decision reinforces the status quo that benefits powerful insiders while leaving working people in the dark.”

So why does Diana “Quixote” continue to tilt at windmills?

It’s personal and political now.

As a legislator, DiZoglio clashed with Spilka over non-disclosure agreements and that bad blood has spilled over now that DiZoglio is auditor and is targeting the Legislature.

But how is this benefitting the voters that DiZoglio is supposed to be serving?

The only one who seems to be benefitting from the ballot question now is DiZoglio consultant Doug Rubin – a longtime Democratic adviser to governors and senators – who is leading the referendum campaign – a fact which was duly noted by Spilka’s lawyers in a recent letter to Campbell.

Rubin is a savvy and experienced adviser but is hurting DiZoglio’s political career by continuing to push the referendum in the face of steep obstacles put forward by Campbell. DiZoglio has been ostracized by the Democratic Party already and has no way of mending fences. She needs a new party.

Maybe the Republican Party and the conservative Mass Fiscal Alliance – which are supporting the referendum movement – can take DiZoglio in.

And DiZoglio can get back to doing what she was elected to do. There is plenty of waste in the government to probe, and DiZoglio should go after that. She can still be a good, tough auditor even without getting a look at the Legislature’s books, which is never going to happen.

Attorney General Andrea Campbell says no to an audit of lawmakers. (Matt Stone/Boston Herald)