Ronald Reagan played another starring role last night -- himself.

As every American politician now knows, no one else brings such a mixture of disarming authority to that portrayal. He was a smash.

Not that his conquering of Congress was any surprise. He had won that battle long before the applause enveloped him on Capitol Hill last night. Congress -- Democrats and all -- came prepared to cheer him, and they did, again and again with genuine emotion.

What gave that scene inside the chamber of the House of Representatives such special emotion were the circumstances of the event.Just one month after he lay wounded, there he was striding through the throngs back into the Congress clearly for all the world to see a political figure of undiminished skill.

And the Congress responded from the first moment they saw him. Anyone looking down on that scene, in that packed center of political power, would have found it hard to believe that this man had been near death only so short a time before. He looked a bit slimmer but aside from that he seemed fully in command and proceeded with energy and enthusiasm through the crowd up to the podium. He was smiling, waving, and clearly enjoying his moment back on the center stage.

It was, in a way, one of Ronald Reagan's most important performances, this carefully staged production highlighting his return to the political arena -- and he didn't muff a line or miss a cue. He brought just the right touch of modesty, just the proper grace notes, to his appearance -- and, consummate player that he is, he injected a note of humor. Reaching inside his coat pocket, he pulled forth an envelope, snapped out a letter and said he had received it from a second-grade student.

The young American had told his president he wanted him to get well quickly -- "or you might have to make a speech in your pajamas."

It brought down the house.

That was not the only time his words touched off an emotional display. There was more than applause that rang out on the Hill last night; there was a keening of emotion, fueled by hoarse shouts and waves from the politicians gathered before him. They were saluting not just a president, come to deliver a political message, but a leader who had survived his brush with death and come back more swiftly than anyone would have expected.

And while Reagan gave his political appeal on behalf of his economic recovery program, it was the personal aspect of the evening that probably carried the most political impact. What Reagan did was thank the people for being so compassionate toward him. He delivered his own little sililoquy of thanks for the messages, the flowers, "and most of all your prayers" that he received after his wounding.

Then, he delivered a sermon, drawing lessons from his experience about the nature of American society today. The response to him, he said, provided "the answer to those few voices that were raised saying that what happend was evidence that ours is a sick society."

He went on to call the roll of those who had fallen beside him -- the Secret Service agent, Tim McCarthy; the District of Columbia police officer, Tom Delahanty, and the public servant, Jim Brady. Each time he called a name the Congress and the assorted diplomatic and other dignitaries responded with thunderous applause.

And each time, the president glanced off to his left to where his wife, Nancy, was sitting gazing down on the scene with a beaming face and rapt attention.

There have been few moments like this on Capitol Hill. Joint sessions of the Congress are commonplace. Presidential messages are routine. Defense of a political course is the stuff of everyday political life in Washington.

But last night's melodrama went beyond these. The very real feelings unleashed in that chamber were testifying to an almost indefinable emotion -- that not just the president had been spared but the country had survived another sudden tearing of the continuity of national leadership.

Reagan's message, in that sense, went beyond the program he was espousing. He was saying, as he did in his campaign, that Americans could start dreaming again. He quoted Carl Sandburg: "The republic is a dream. Nothing happens unless first a dream."

It was a time for optimism, the president was saying, and a time in which "we have much greatness before us." He read the lines like a master and, in his final scene, was threading his way back through the cheering crowd and on to his next political act.