We are surrounded on all sides by news of criminal investigations into politicians. Robert Mueller, the special counsel, has obtained an indictment relating to his investigation into possible collusion between the Trump campaign and the Russian government. Congressional committees are also investigating Russian meddling in the 2016 election. House Republicans have announced plans to look into the Obama administration’s handling of Hillary Clinton’s emails and its decision to give a Russian-controlled company, Uranium One, control of some American uranium reserves. Now the Justice Department is considering whether to appoint a special counsel in the uranium deal.

Government corruption should be prosecuted, Congress has a role to play in overseeing the executive branch, and our intelligence agencies are right to raise concerns about foreign interference in our elections. But there is something worrisome about the current frenzy of criminal investigations. To me they point to a frightening trend that afflicts both Democrats and Republicans: the criminalization of political differences.

The framers of our Constitution did not seek to make it easy to convict Americans of crimes. They bestowed upon criminal defendants a bundle of rights to provide safeguards against overzealous prosecutors or legislators, including prohibitions against compelled self-incrimination, unreasonable searches, double jeopardy and the passage of laws declaring people guilty of acts that were not criminal when committed.

Our legal system also came to require proof beyond a reasonable doubt, a unanimous jury and clear statutes that differentiate between criminal and noncriminal conduct. No wonder Benjamin Franklin described our system as preferring that “a hundred guilty persons should escape than that one innocent person should suffer.”