There wasn't a Stetson or six-shooter in sight as the black-tie crowd of 400 milled and ate and drank and danced. But there was a definite goll-dang-it, go-get-'em flavor to the twanging, drawling conversation that filled the Four Seasons hotel ballroom last night.

And the dinner-dance benefit for the Washington International Horse Show provided a rootin'-tootin' city-slicker preview of Sunday's Western Night opener when all pardners are invited to sashay down to the Capital Centre, gussied up in their latest down-home duds.

"The guys and gals are certainly whoopin' it up tonight, " observed one guest to no one in particular, just before he bellied up to one of the five bars for another hit of the usual.

"Good evening, senator, and congratulations," said another as he clasped his right hand into Sen. Barry Goldwater's (R.-Ariz.) much-pumped right hand and gave it a manly shake, emphasizing the sincerity of his feelings with an "I hope it prevails."

He was referring to the recent decision that Congress must pass on the phasing out of the treaty between the U.S. and Taiwan, a decision that Goldwater had fought for.

True to the strong, silent prototype out of the American West, Goldwater modestly shrugged off the well-wisher with, "It's not a victory for me, it's a victory for the Constitution.

"It's those nitwits at the State Department, who did it," he said, warming to the topic. "You know there are two different State Departments -- the eighth floor where the secretary has his offices and all the other seven floors that run the show. I was hoping that Carter would do what no Republican has been able to do and clean that place out."

"Goldwater is a good man," said horse and cattle breeder Paul Summers, "but he's a little reserved for me. He only speaks out when he has something to . . . (uh) . . . do." Summers, who was wearing a Connally name tag, was more than willing to expound on his favorite topic.

"I've been over cheering Connally and I'm not ashamed to admit it," said Summers, who was not the only guest sporting a Connally name tag. "He doesn't pussyfoot around, and we need somebody to speak out. We need an aggressive man in the White House. Connally made a rip-snortin' good speech."

"This is where you'd expect to find a lot of the Connally crowd," confided one of the gala's organizers, "He's got all the corporate types and they have come over here now."

Rep. Jim Mattox, a Dallas Democrat, however, wasn't much interested in the affairs of his fellow Texan. He was there to talk horse shows. "They're for good causes and there are always beautiful horses."

As for Connally, Mattox said, "I'm a very partisan Democrat so I've never had anything to do with him. I never supported him. He's always been a Republican as far as I'm concerned -- he's just turned honest."

Honesty, or at least candor, was a big item last night and it got bigger as the evening moved on, gathering momentum until it became a tell-it-like-it-is stampede.

"Nice of you horse people to let me in again this year, in view of the allergies and all," said Air Force Gen. Samuel K. Lessey Jr., who confided that he can't get near a horse -- or a dog or a cat, for that matter. Nevertheless, Mignon Smith, who "is a fox hunter at this stage," was glad to see him. She didn't even mind the reference to "horse people," although seh later confided, "It's all right when you are talking about a group of us, but I am a horsewoman, not a horseperson. I don't want to be neuterized."

Most decidedly not neuterized was another horsewoman, Rose Marie Bogley, who held court dressed in a lowcut, full-sleeved Bill Blass gown.

"She's what makes the horse show. Her glamor and prestige truly make the whole thing realistic," was the sotto voce evaluation of interior designer Bob Waldron.

For Bogley, however, there was an air of unreality about the evening. "Would you believe," she said "that after this dance, I'll return to Middleburg and take another lesson tomorrow afternoon? I've been riding in the sidesaddle class for 10 years now. I came in second in the first one and I have never done as well since. I want to do it this time. I am lessoned to death. I'm so horsed out that I think if I get through the month of October, I'll be able to do anything. I could even run for president."