Whatever your taste in politics or poetry, this was a charming moment. Rep. Claude Pepper, the 81-year-old congressman from Florida, was speaking over the phone with 89-year-old friend Archibald MacLeish. "I hope you're enjoying life," said Pepper, who placed the call from his House office to MacLeish in the poet's home in Massachusetts. "Other than your little hearing impairment, I hope your physical condition is good. You've got eight years on me! I'm only 81. You give me something to shoot at!"

Pepper laughed jovially. He chatted for 10 minutes with MacLeish. The congressman had phoned America's greatest living poet for his advice about a joint sesson of Congress late in January to observe the centennial of the birth of Franklin D. Roosevelt. MacLeish suggested some appropriate FDR readings, which was why Pepper had phoned.

For the representative, who is called "Senator" because he served from 1936 to 1950 in the Senate, the phone call was part of another workday made radiant for him, and others, by his love of politics and affection for people.

A few days earlier, Pepper was in the national eye at the White House Conference on Aging. In the weeks before, his office had received 130 requests for interviews. For a little while, that may have made the Miami Democrat the most sought after member of Congress. But on a higher level it was a coalescence of interest in one of American politics' unique figures.

As chairman of the House Select Committee on Aging, Pepper has maintained a mountain-high vision of what government should be doing to better serve its elderly. With more than 4,000 citizens turning 65 every day, and 25 million already there, Pepper represents this national constituency as a pugnacious but reasonable advocate. Rather than relaxing and using his committee job as a laureateship, he has turned it into a center of concern for the elderly.

This was the committee that the House never even wanted to let in the front door. It began in the early 1970s when Sen. David Pryor (D-Ark.), then a representative, rented a trailer and held unofficial hearings. Pryor had worked incognito in a nursing home where he witnessed the shabby treatment given to the elderly.

When Pepper took over the committee, he was familiar too -- in personal ways -- with the abuses visited upon the old. Nearly every issue involving the elderly to come before Congress -- from restrictive mandatory retirement laws to malnutrition among the old -- has engaged Pepper. Behind his legislative zeal is a philosophical attachment to Shaw's notion about the old: "Some are younger at 70 than most at 17."

The hour and a half I had with Pepper the other morning was to enjoy an uplifting mixture of history lessons, political nuances and ideals of public service. Pepper gives personality to a style of hearty liberalism now out of fashion, at least temporarily.

The abandonment of liberalism by some of the younger politicians in Congress springs from two causes, he believes. First, they came to Washington not "deeply rooted in liberal convictions." And second, once here "they don't want to be identified as liberals because they think public opinion has turned away from the humanitarian influence in public affairs . . . They are fearful of their political lives, and they think that (liberalism) has come to have an unfavorable association."

Of the nine presidents Pepper has served under, he gives a low ranking to Ronald Reagan. With animation, he says that Reagan "comes the nearest to having the charm of President Roosevelt. But I would think that one would be unhappy to have it said that I'd hardly done anything that was meaningful in any affirmative way for the people of my country. Now he wants to cut more and more and more."

Pepper felt honored that Reagan mentioned him in his speech at the conference on aging. But, wistfully, he says he has never met the president. The night before our conversation, Pepper had been to the White House for "an official hosting" of the Congress. But Reagan went upstairs early and missed the chance to talk with Pepper, leaving the Senator to say: "I had rather looked forward to meeting the president."

Should Ronald Reagan's spirit ever sag in the year about to dawn, one sure pick-me-up would be a long visit with Claude Pepper.