Sen. Margaret Chase Smith took the floor of the United States Senate on June 1, 1950, and delivered a short speech. In the half-century since, those four minutes or so have become the crowning moment of a long and distinguished Maine life. The words “Declaration of Conscience” have been transformed from the mere title of a speech to a potent reminder that the freedoms at this nation’s core are strong and at the same time fragile.

The speech itself, reprinted on the opposite page, is a marvel of brevity, directness and plain speaking. Everyday phrases, such as “The American people are sick and tired of being afraid to speak their minds,” far outnumber those attempting grand oration — the “four horsemen of calumny” make only one brief appearance. The “I speak as a Republican… as a woman … as a senator” sequence is developed in such a way that it was hardly necessary for her to state that she was speaking mostly as an American. The essential point — that the United States can and must protect its national security without sacrificing liberty, integrity or honesty — is clearly stated and often reiterated.

The simplicity of the speech disguises its political sophistication. Sen. Smith blasted all who had joined the escalating war of name-calling and baseless accusation. She scolded the Democrats, the Truman administration in particular, for ineptitude and ineffectiveness. Her strongest criticism though, criticism that added to her credibility, was directed at fellow Republicans for engaging in conduct unworthy of the party of Lincoln.

But beyond content and style is courage. If time has been unkind to this speech and its remarkable author in any way during the last 50 years it is in the common perception that the “Declaration of Conscience” marked the beginning of the end for Sen. Joseph McCarthy and the witch-hunting “ism” that bore his name.

In fact, Sen. Smith stood up to McCarthy at the very beginning of his four-year rampage. Hundreds of baseless charges and ruined careers were yet to come, as were televised hearings and McCarthy’s pledge that he would bury the senator from Maine. Sen. Margaret Chase Smith did not measure public opinion and give a speech from the bandwagon. She knew what was right, even if it was unpopular, and 50 years ago today on the floor of the United States Senate she stood alone and said it aloud.