Almost nothing amazed me more in my eight years working for Sen. Edward Kennedy than realizing that he was nervous just before he gave a speech on the Senate floor. Not always, but often. And it wasn’t for a lack of experience or preparation.

[IMGCAP(1)]The morning of a speech, the Massachusetts Democrat would draw his staff together, and we would prepare in his office as if for a grueling oral exam. No one wanted to be the staff member who didn’t know the answers to one of his questions.

When he was debating an increase in the minimum wage, for example, it wasn’t enough to tell him how many returned Iraq War veterans were working for the minimum wage — we had to figure out how many spouses of those currently serving were making minimum wage.

We would do our best to anticipate his questions, but every day on the floor with Kennedy we’d face a minor crisis or three — an unanswered question or a piece of missing information. Of course, we had staff back at our office standing by for just such a call, and we had a pool of outside sources who would turn on a dime to help the Senator.

He was a visual thinker and loved using charts to illustrate his points. We had prepared more than 100 charts on the economy, and he had stacks and stacks of charts on health care, education and other issues he held dear. We learned with experience that he was more likely to make a particular argument if we created a chart than if we included it in the written speech.

The minutes before the speech were often tense. The Senator wanted to hear the major points repeated back to him, and he wanted to quickly run through dozens of charts to put them in order. Just before speaking, Kennedy also would have Beth, his assistant, call his sister Jean in New York so she could turn on C-SPAN to watch him. We never knew whether it was brotherly love or a need to picture someone in the television audience whom he could address.

The Senate floor is smaller than one would expect, and most of the time, it is a hushed, almost lonely place. A junior Senator presides while signing letters or catching up on reading. The high school pages deliver bills and fill water glasses. The parliamentarian reviews documents. The party secretaries quietly negotiate the next votes.

Then Kennedy would break the silence by delivering yet another stem-winder from his back-row desk. He was not a tall man, particularly when I knew him in his 70s, but he had an outsize physical presence with his large head and famous shock of Kennedy hair. Most of all, he was an orator in the grand Senate tradition. His speeches brimmed with passion.

Like a star pitcher with a long windup, Kennedy never rushed his delivery. He liked to start out deliberately, lay out his position, then build to a peak. He generally began with the written text, but quickly left it after a page or two — often, to read from a primary source, particularly the underlying bill. He would then cite a study — holding it up and waving it around with a reference to the highlighted and annotated pages — before turning to his stacks of charts, which allowed him to improvise off a series of themes and arguments.

With each passing minute, Kennedy’s voice grew louder, his gestures larger and his face redder. The high school pages would stop and gather around the rostrum to sit and listen to the thunder. The pack of reporters in the press gallery would grow. Like the civil rights leaders he knew and so admired, Kennedy’s best speeches were filled with rhythm and repetition.

For a six-month stretch during the last recession, Kennedy spoke on the floor about the economy almost every day. He spoke of the dignity of work and the pain of unemployed workers and their families. He reminded us of growing inequalities in wages and wealth. He told us how some parents were working harder and harder but still couldn’t make ends meet. Workers, he said, should be safe on the job and they should be able to join a union. He declared that parents shouldn’t have to choose between the kids they love and the jobs they need. And he said that no one who works for a living should have to be in poverty in a country as great as the United States.

Finally, spent and dripping with sweat, the Senator would conclude. He would thank us on the way out the door, and we’d return to our offices to prepare for another grueling, thrilling day in the Senate.

His voice has been silent a year now, but his messages are as relevant as ever. He was a great man because after decades of public service, he still cared — about the major issues of the day, about the people who needed his voice and about winning on their behalf.

Holly Fechner is a lawyer at Covington & Burling. She was Kennedy’s policy director and chief labor counsel from 1999 to 2007.