When John Connally came striding into the big meeting room, parading through the glare of TV lights and the roar of applause, Frances Gaylord let out a large yawn.

Gaylord, a Republican activist from Lafayette, Ind., had been up late Friday night partying with friends here at the Midwestern Republican Leadership Conference. This morning she dutifully sat through presentations from six potential presidential candidates, and by the time Connally's turn came she was almost asleep.

Thirty minutes later, when Conally had finished his arm-waving, palm-slapping, slambang sermon on the need to "revive America's strength," Gaylord was wide awake and on her feet to add to the standing ovation for the silver-haired Texan.

"Why, I never knew he was so -- what's the word? -- so dynamic, that's it," Gaylord said. "He's just more dynamic than the others."

Sure enough, when the CBS News preference poll was distributed, Frances Gaylord put down John Connally as her first choice for president.

Gaylord's awakening to the Connally mystique captured in a nutshell the story of this GOP gathering. Although all the would-be presidents on hand received a warm response, it seemed clear that Connally's was the warmest of all.

Whether this means anything is less clear. There are after all, 71 weeks remaining before the Republicans nominate their presidential candidate, and most of Connally's competitors are not yet fully geared up for the race. Several likely candidates, including the early favorite, Ronald Reagan, didn't bother to come to this conference.

Organizers of the annual affair were astonished at the number of people who did show up.

In a normal non-election year, about 100 of the hardest-core party activists would be on hand, and they would have to scramble to find enough prominent speakers to fill the program.

Now, with conventional wisdom holding that a successful presidential campaign must be a two-year effort, the Midwestern Republicans had no trouble scheduling appearances by six presidential hopefuls (seven, counting Harold Stassen, who was not on the program but showed up anyway).

The mad momentum of the presidential jockeying attracted 600 otherwise sane Republicans to a weekend in this grimy city, along with a full cohort of the reporters, pollsters, advance men and other camp followers who show up wherever political people congregate.

The highlight was this morning's three-hour session in which the six possible presidential contenders each made a pitch for support. They agreed, in the main, on the major issues -- inflation at home and American prestige abroad -- but there were striking differences of style and character on display.

Sen. Howard Baker of Tennessee came across as a knowledgeable and not terribly exciting analyst of issues, although he was able to come up with some tub-thumping oratory to spark a warm ovation as he left the podium.

George Bush, the New England Brahmin turned Texan, spoke in the moderate, businesslike tones of a board chairman reciting the latest sales figures at the stockholders' meeting.

Rep. Philip Crane of Illinois, sounding like the history professor he once was, set forth a theoretical framework of the meaning of liberty.

Rep. Jack Kemp of New York was an energetic cheerleader for his position that a drastic tax cut is needed "to get the most productive society man has ever known working again."

Sen. Bob Dole of Kansas was his usual wisecracking self, getting off two gags in the first 15 seconds of his speech and then launching into a long complicated joke about an army battalion that lined up in the rain to watch Haley's Comet -- or something like that. Dole then proceeded to offer the most thoughtful speech of the day, calling for positive Republican initiatives in agriculture, health care, and energy resources. But he closed with another round of jokes and it was hard to tell when he was being serious.

And then there was Connally. It was not so much the content of his speech that captured the crowd as his cocky, commanding self-assurance and his declaration that President Connally would be strong in all the areas where he found President Carter to be weak.

When the CBS poll was tabulated Connally ran away with the balloting for "best speaker" and showed up as the Midwest Republicans' first choice for the presidential nomination.

Connally was favored by 29 percent of those polled, with Reagan following at 22 percent and Bush third with 18.

Connally's reception was almost matched, though, on Friday when Stassen was introduced at a preliminary session. The 71-year-old perennial candidate stated his case with reason and dignity, and then sat down with a quiet smile as the applause welled up around him.