MADISON, Wis. — Milwaukee County District Attorney John Chisholm has broken his usual “no-comment” silence on all things John Doe by firing off a very public and very confrontational response to Gov. Scott Walker. First Amendment and other legal experts have blasted the partisan prosecutor’s rhetoric as somewhere between childish and downright scary. Could the man who brought Wisconsin its notorious John Doe investigations face professional sanctions for suggesting Walker could face criminal defamatory charges for criticizing Chisholm’s investigation? Maybe, but actual charges probably aren’t likely, legal ethics experts tell Wisconsin Watchdog, although many agree Chisholm’s threatening language is troubling....