The United States has experienced deep political turmoil several times before over the past century. The Great Depression caused Americans to doubt the country’s economic system. World War II and the Cold War presented threats from global totalitarian movements. The 1960s and ’70s were marred by assassinations, riots, a losing war and a disgraced president.

These earlier periods were each more alarming in some ways than anything that has happened in the United States recently. Yet during each of those previous times of tumult, the basic dynamics of American democracy held firm. Candidates who won the most votes were able to take power and attempt to address the country’s problems.

The current period is different. As a result, the United States today finds itself in a situation with little historical precedent. American democracy is facing two distinct threats, which together represent the most serious challenge to the country’s governing ideals in decades.

The first threat is acute: […]