WASHINGTON (AP) — It's a good thing Richard Nixon was such a klutz.

The president's ineptness at all things mechanical is what prompted his aides to install a voice-activated recording system that didn't require Nixon to push an on-off button, ensuring that every word he spoke in the Oval Office and other key locations was caught on tape.

With the secret taping system on autopilot — seven microphones planted in wall sconces and the president's desk — Nixon largely forgot about it, and let loose with the raw, gossipy, conniving and too-clever words that ultimately toppled his presidency and forever changed the way Americans think about their presidents and their government.

The tapes — the last installment of them released Wednesday — are like the black box in an increasingly out-of-control airplane, recording right up to the crash.

In the tapes, Americans began to see their presidents as "less glorious, less heroic, less romantic — either more like us, or more like people we don't like," says presidential historian Julian Zelizer of Princeton University....