Kimberly Strassel of the Wall Street Journal explains in the latest edition of Hillsdale College’s Imprimis how the political left has responded to the Citizens United case’s role in ending free-speech restrictions.

In the weeks following the Citizens United ruling, the Left settled on a new strategy. If it could no longer use speech laws against its opponents, it would do the next best thing—it would threaten, harass, and intimidate its opponents out of participation. It would send a message: conservatives choosing to exercise their constitutional rights will pay a political and personal price.

We’ve seen this strategy unfold, in a coordinated fashion and using a variety of tactics, since 2010.

One tactic is the unleashing of federal and state bureaucracies on political opponents. The best example of this is the IRS targeting of conservative non-profits. To this day, Obama acolytes and Senate Democrats characterize that targeting as a mistake by a few minor IRS employees in Cincinnati who didn’t understand the law. That is a lie. …

… Another intimidation tactic is for prosecutors to abuse their awesome powers in order to hound and frighten political opponents. The most terrifying example of this was the John Doe probe in Wisconsin. Democratic prosecutors in Milwaukee launched a bogus criminal campaign finance investigation into some 30 conservative groups that supported the public-sector union reforms championed by Governor Scott Walker. Wisconsin’s John Doe law gave these prosecutors the right to conduct this investigation in secret and to subject their individual targets to gag orders. Prosecutors secretly looked through these individuals’ financial records, bank accounts, and emails.

Prosecutors also conducted pre-dawn raids on some of their targets’ homes. …

… A third intimidation tactic is for activist groups to use blackmail against corporations and non-profits in order to silence them. One subject of such attacks was the American Legislative Exchange Council (ALEC), a group that works to promote free-market policies at the state level. As a non-profit, it is largely funded by corporate donations. Because it is so successful, it has long been despised by left-wing activist groups.