Twenty-eight minutes into the first televised debate of the 1980 presidential campaign, Sen. Bob Dole looked out at the audience. "I hope you're having fun," he said. "We are."

As a matter of fact, the audience was in a good-natured uproar. A moment before, John Connally, the blustery Texan who is seldom at a loss for words, had been cut speechless when asked to tell how he differed from GOP front-runner Ronald Reagan.

Connally quickly recovered, declaring, "I wish Governor Reagan were here. Oh, I wish he were here. I don't know where the governor stands."

The remarks opened the floodgates. Soon each of the other five Republicans at the debate were criticizing Reagan's absence.

The politics of 1980 may or may not have gained much from the debate, but it gave the voters of Iowa and television viewers across the country their first good look at the Republican field on the same platform.

All of them needed the exposure. With Reagan a runaway leader in the polls, they are all competing for attention.

The debate was held at the new 2,600-seat Des Moines Civic Center, Iowa's version of the Kennedy Center with only slightly better architecture. iThe atmosphere was like an opening night.

For the theater, it was a better opening than most had dared expect. The candidates, particularly Dole and the normally conciliatory Sen. Howard Baker, came to the affair hungry for blood.

By the luck of the draw, Rep. Philip M. Crane, the longshot conservative candidate, was seated on the far right of the gray-carpeted podium. George Bush was on the far left.

They were both judicious, guarded, almost somber, the gray judges on the bench.

Dole, who has the weakest organization in Iowa, had the best lines, the glibbest tongue. In answer to a question if he had any regrets in his public career, Dole replied, "I once called Carter chicken-fried McGovern. I take that back. I've learned to respect [South Dakota Sen. George] McGovern."

Asked how he could cut taxes, increase military spending, balance the budget and end inflation as president, he first replied only, "It's going to be difficult."

Then he added, "That's why we have to be very careful of who we pick as candidate."

Dole's light-heartedness seemed to mask deep inner tension. Both he and Bush, who sat at his right, came onto the stage looking taut and drawn. Baker, Anderson and Crane looked relaxed by contrast, joking among themselves.

Anderson, who is not contesting the Iowa caucuses, had less to lose in the debate than any other candidate. He was the only one to question the conventional wisdom as questions from panelists moved from candidate to candidate. He appeared to enjoy every minute of it.

And how did the debate play in Des Moines?

"I liked the Pope better," one young man said as he left the event.