“The central question,” Senator Howard Baker (Republican of Tennessee) said on this day in 1973, in an effort to focus the minds of a crowded room, “is what did the President know? And when did he know it?”

He was questioning John W. Dean III in pursuit of the elusive truth about the welter of misdeeds known as Watergate. If those misdeeds failed utterly to destroy the American republic, it’s because the Congress and the courts exposed them, with the help of members of both parties, and passed laws to prevent their recurrence.

And at the time–in the middle of a long, drawn-out, ideological war–the administration was not shy of shouting “national security” every time it seemed its secrets might get out.

But the courts weren’t having it; as Justice Black had written two years before, “The word ‘security’ is a broad, vague generality whose contours should not be invoked to abrogate the fundamental law[.]”

Amid the general threat posed to the United States by the expansionist ambitions of the communist Soviets, a general threat sharpened by the specific need to support our troops mired in a war whose purpose was uncertain and end indefinite, the repeated claim that it would imperil national security to expose what the administration had done in the name of American citizens gained force.

Yet some politicians managed to do the right thing anyway, to ignore that specious claim, and seek the truth.

For the Baker quotation: Christopher Lydon, “Dean Navigates Watergate Shoals with Ease,” NYT 6/29/1973, p. 22.