Marquette University law Prof. Rick Esenberg:

In response to Governor Scott Walker’s reference to the John Doe investigation as unconstitutional and a political witch-hunt, Milwaukee County District Attorney John Chisholm implied that Walker could be prosecuted for criminal defamation.

Here’s the likelihood that could happen. Zero. Zilch. Nada. Not in this country.

Now, I assume that John Chisholm knows that. I assume that he knows that because any lawyer with even the slightest background in First Amendment law would know it. I assume it because the alternative is a frightening, I would hate to think that a lawyer who has the power to charge people with crimes and presumes to exercise that authority in areas like campaign speech and finance does not know the constitutional obstacles to charging people with a crime for speech.

According to the First Amendment Center, Iowa has no criminal defamation statute, although (oddly) there have been efforts to prosecute people for such an offense. For reasons that I won’t get into here, it is an open question whether any such prosecution would be constitutional in this context. But anywhere in the United States, a prosecutor who sought to bring such charges would, at minimum, be required to prove beyond a reasonable doubt that Walker made statements of fact (not opinion) and that he knew they were false or acted with reckless disregard for their truth or falsity. Simply proving that he was “wrong” (if that even could be done) wouldn’t cut it.

I’d as soon put my money on the 4-15 Brewers winning 100 games this year.

In response to the same statement by Walker, prosecutor Fran Schmitz calls on Walker to support public release of the documents that Walker believes Schmitz gathered improperly. That’s also scary talk from a prosecutor. There is a legitimate question as to whether the seizure of private records of political activists was proper. In fact, the only two judges who have ruled on the question have found that it was not. In other words, it seems possible – I’d say probable – that Schmitz should not have the records that he now wants to make public.

If these records were improperly seized, releasing them would make the injury to these activists irreparable. What they had a right to keep private would now be permanently public. Yet Schmitz seems to be suggesting the best response to an allegation that prosecutors should not have seized private records is to make them public.

Esenberg adds on his own blog:

Imagine, for a moment, that this had been done to a newspaper or broadcast operation. Assume an early dawn raid on the Milwaukee Journal Sentinel’s offices at Fourth and State in which reporters’ files were carried away and editors were told to keep their mouths shut about what had been done to them. (The prosecutors here did contemplate going after broadcast journalists.) Our newspapers and broadcast stations would be apoplectic about the “chilling impact” on freedom of speech that such tactics would have. And rightly so. …

The elected District Attorney of Milwaukee County actually suggested that someone who criticized him should be charged with a crime.

Let’s start with the easy part. This is the type of statement that will get earn a law student a very bad grade in Constitutional Law. The question is not whether Walker was “right” or “wrong.” At minimum, one would have to show that Walker made statements of fact (not opinion). At minimum, one would have to show, beyond a reasonable doubt, that he knew the statements were untrue or acted with reckless disregard of their truth and falsity. Even then, there remain serious constitutional questions regarding the criminalization of political speech.There is no way – not in this country – that such a prosecution could ever succeed.

But the problem here is larger than a single lawyer’s understanding of constitutional law or appreciation for the First Amendment. Any lawyer who suggests that political speech should be criminally prosecuted might expect to be laughed at. But when that lawyer has the power to invoke the machinery of the criminal law, it is no longer a laughing matter.