The early-morning paramilitary-style raids on citizens’ homes were conducted by law enforcement officers, sometimes wearing bulletproof vests and lugging battering rams, pounding on doors and issuing threats. Spouses were separated as the police seized computers, including those of children still in pajamas. Clothes drawers, including the children’s, were ransacked, cellphones were confiscated and the citizens were told that it would be a crime to tell anyone of the raids.

Some raids were precursors of, others were parts of, the nastiest episode of this unlovely political season, an episode that has occurred in an unlikely place. This attempted criminalization of politics to silence people occupying just one portion of the political spectrum has happened in Wisconsin, which often has conducted robust political arguments with Midwestern civility.

From the progressivism of Robert La Follette to the conservatism of Gov. Scott Walker (R) today, Wisconsin has been fertile soil for conviction politics. Today, the state’s senators are the very conservative Ron Johnson (R) and the very liberal Tammy Baldwin (D). Now, however, Wisconsin, which to its chagrin produced Sen. Joe McCarthy (R), has been embarrassed by Milwaukee County’s Democratic district attorney, John Chisholm. He has used Wisconsin’s uniquely odious “John Doe” process to launch sweeping and virtually unsupervised investigations while imposing gag orders to prevent investigated people from defending themselves or rebutting politically motivated leaks.

According to several published reports, Chisholm told subordinates that his wife, a teachers union shop steward at her school, is anguished by her detestation of Walker’s restrictions on government employee unions, so Chisholm considers it his duty to help defeat Walker.

In collaboration with Wisconsin’s misbegotten Government Accountability Board, which exists to regulate political speech, Chisholm has misinterpreted Wisconsin campaign law in a way that looks willful. He has done so to justify a “John Doe” process that has searched for evidence of “coordination” between Walker’s campaign and conservative issue advocacy groups.

On Oct. 14, much too late in the campaign season to rescue the political-participation rights of conservative groups, a federal judge affirmed what Chisholm surely has known all along: Since a U.S. Supreme Court ruling 38 years ago, the only coordination that is forbidden is between candidates and independent groups that go beyond issue advocacy to “express advocacy” — explicitly advocating the election or defeat of a particular candidate.

But Chisholm’s aim — to have a chilling effect on conservative speech — has been achieved by bombarding Walker supporters with raids and subpoenas: Instead of raising money to disseminate their political speech, conservative individuals and groups, harassed and intimidated, have gone into a defensive crouch, raising little money and spending much money on defensive litigation. Liberal groups have not been targeted for their activities that are indistinguishable from those of their conservative counterparts.

Such misbehavior takes a toll on something that already is in short supply: belief in government’s legitimacy. The federal government’s most intrusive and potentially punitive institution, the IRS, unquestionably worked for Barack Obama’s reelection by suppressing activities by conservative groups. Would he have won if the government he heads had not impeded political participation by many opposition groups? We will never know.

Would the race between Walker and Democrat Mary Burke be as close as it is if a process susceptible to abuse had not been so flagrantly abused to silence groups on one side of Wisconsin’s debate? Surely not.

Gangster government — Michael Barone’s description of using government machinery to punish political opponents or reward supporters — has stained Wisconsin, illustrating this truth: The regulation of campaigns in the name of political hygiene (combating “corruption” or the “appearance” of it) inevitably involves bad laws and bad bureaucracies susceptible to abuse by bad people.

Because of Chisholm’s recklessness, the candidate he is trying to elect, Burke, can only win a tainted victory, and if she wins she will govern with a taint of illegitimacy. No known evidence demonstrates any complicity in ­Chisholm’s scheme, but in a smarmy new ad she exploits his manufactured atmosphere of synthetic scandal in a manner best described as McCarthyite. Indeed, one probable purpose of Chisholm’s antics was to generate content for anti-Walker ads.

Wisconsin can repair its reputation by dismantling the “John Doe” process and disciplining those who have abused it. About one of them, this can be said: Having achieved political suppression by threatening criminal liability based on vague theories of “coordination,” Chisholm has inadvertently but powerfully made the case for deregulating politics.

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