THE COLOSSEUM BANQUET and Function Room, where Ronald Reagan brought his presidential campaign last month, is a curious restaurant. Squatting in the middle of a glass-strewn parking lot overlooking a smelter, the Colosseum is a little bit of Italy in West Springfield, Mass. After all, there is the Toga Room. And the Julius Room, and the Caeser Room. And the place is curved, in stucco appreciation of the real thing. And there's marble in the bathrooms, except it's peeling near the sinks, where the water has soaked off the backing.

Close up, you can see the pencil lines on all the posters, drawn to make sure the tempera slogans come out nice and straight. 18 by 15 inch slices of white cardboard, they hang square-cornered around the room, like paintings for sale in the lobby of a tacky movie theater. All red, white, blue, and black, all a little scary. The B-1: A Necessary Vitamin to Ward Off the Red Disease. Win One for the Gipper: Reagan 1980. Help Put the Laffer Curve to Work for Reagan. Big Government is the Enemy Within. Table SALT. And stretched across the front, in big red letters, Remember the Canalamo.

Luncheon guests trickle in, the first an hour before Reagan is scheduled to arrive. The master of ceremonies begins the proceedings by pointing out luminaries; the biggest hand for the chairman of the East Longmeadow Republican Town Committee. Reporters, most of them from local radio stations, stand attentively in the roped-off press area, their secret service badges pinned on conspicuously, so all can know they are members of the "Press Corps." The Secret Service men don't have much to do--hostility looks beyond the emotional range of most of those occupied with the turkey roll. So they talk about the coat check girl, or rather about her generous, black-sweatered bosom.

There couldn't be a better setting for Ronald Reagan--like the Toga Room, an imperfect relic of a different age. Reagan outlines for the crowd his solution to the Afghanistan crisis--a blockade of the island nation of Cuba, nothing in and nothing out until the Soviets withdraw from the Afghan nation. "All we've been doing is reacting. Why don't we give them something to think about, like Cuba?" he suggests, to cheers. "I think it's time we quit telling the enemy what we won't do, and letting them go to bed at night wondering what we might do." More cheers. Reagan is building to a climax. "The president told us SALT II had to be ratified or no one would like us. He told us we had to give away our canal or no one would like us. It's time to tell the president we don't care if other countries like us, that instead we want to be respected." Standing ovation.

LATER, A HALF-HOUR alone with the man shows nothing further underneath. Ask about nuclear--Reagan will lean forward, voice husky with sincerity and with the strain of endless campaigning. "I wish students would look into the entire problem, so they could see the refutation that is available," he says. Now expansive, leaning back, reciting Guiness-Book evidence. "Even Three Mile Island, and that was worst, had less radiation than flying coast-to-coast on an airplane. Less radiation than living at the altitude of Denver." Reassuring, even compassionate now, Reagan switches topics; he counsels young people not to protest against the draft, for it will only make them look "silly and unpatriotic," just like "those ones in the sixties."

The rhetoric, the posters, the silent wife who fits snugly into the curve under his shoulder, are convincing. Ronald Reagan is not a subtle man; while it is likely that during his tenure the Communists (or, if you prefer, "the enemy") will go to bed at night less sure of their safety, it is also true that many Americans may sleep more fitfully. "You can bet Communists aren't going to move until it's a sure thing. What we must do is send them some signals."

Reagan is watching his campaign slowly slip away, the sand crumbling under his feet, like a kind trying to stand in the backwash of the surf. There are still hopeful signs; Reagan speaks of a "national constituency" explaining that Iowa (and, perhaps, New Hampshire) aren't as important as America. And downstairs, a middle-aged woman tries to get into the "security area" the Secret Service man have set up around the candidate. She is armed with a Canon AE-1, 200 mm lens firmly attached. "I don't know how to use this; it's my son-in-law's. But I must see Mr. Reagan. He's so good-looking."

However, this is 1980, and definitely Reagan's last shot at the presidency, not because he is old, although he is, but because he is Reagan, a conservative. Not a neo-conservative or a subtle conservative, but a conservative who likes talking tough, who believes in the slogans, who looks at the world from the perspective of World War II and Korea instead of mouthing meaningless, magic phrases like "geopolitical linkage." His ideas are not slick, not sophisticated. They are firm, not greasy like Baker's or Bush's or Jimmy Carter's.

Cascades of balloons used to be a staple of political functions, back in the days when "party regular" was a title of respect and market research was just a glimmer in some Madison Avenue mind. Convention after convention, speech after speech, they'd release the balloons, each weighted with a drop of water, at the climatic moment. Today, the balloon drop is a dying art form. But for Reagan it looks appropriate; the huge plastic bag, pregnant with balloons, hangs from the ceiling of the Toga Room, waiting to deliver on cue. Nowadays, though, it's hard to find anyone who can engineer the spectacle. Reagan brought the audience to its feet at his close, looked skyward--nothing. Half an hour later, they were still trying to shake the balloons down.