The candidate glances apprehensively at his watch, grimacing when he realizes he is running 15 minutes behind schedule. His advance man, trying to relax his boss, tells him of the time vice presidential hopeful Sargent Shriver arrived three hours late for a rally in New Hampshire during the 1972 campaign, only to find no one there. The candidate responds jokingly that it would have made no difference if Shriver were on time; no one would have been there anyway.

* * *

But for Rep. Paul Tsongas, who is campaigning for Ed Brooke's U.S. Senate seat, time is crucial. The polls show that Tsongas is running well behind the front runner, Secretary of State Paul Guzzi '64, in the race for the Democratic nomination. A poll taken about a month ago by Pat Caddell '72, President Carter's favorite pollster, showed Guzzi had three times more support than Tsongas, and that the Congressman was even 1 per cent behind the other major candidate, Boston School Committee member Kathleen Sullivan Alioto. Tsongas's own poll, taken slightly after the Caddell poll, shows him to be in second place, but still well behind Guzzi.

Tsongas, however, has grown accustomed to his current catch-up position--he came from behind four years ago to beat the Republican incumbent for the right to represent Massachusetts' Fifth District in Congress. But as he pointed out three weeks ago, that time he campaigned for 21 months and still only had to win over the residents of a single district. This time has has only five months to convince the six million people throughout the state to vote for him.

There are some indications' that Congressman Tsongas might be able to win over enough of those six million to catch Guzzi. Tsongas's poll shows Guzzi, holder of a very visible statewide office, is leading largely on the strength of his greater exposure. Among those voters familiar with all three major candidates for the nomination, however, Tsongas wins, advance man David Goldman says. Another point in his favor, Tsongas adds, is that projections show he is capable of raising more money than Guzzi. Both candidates, however, will raise less than Alioto, who has at her disposal the personal wealth of her father, owner of Metropolitan Oil and the New England Patriots football team, and her husband, the former mayor of San Francisco.

It appears that Tsongas's chances rest on his ability to use the money he raises to increase his exposure in areas outside of his home district--especially the western part of the state. So far, the efforts aimed at making "Tsongas" a familiar name seem to have been fairly successful: a television and radio campaign in western Massachusetts has doubled the candidate's visibility, Goldman says. Now, in hopes of doing the same in the east, and because he can afford the $2000-and-up price-tag of a 30-second slot of air time on Boston television stations, Tsongas just last week began airing spots on the local channels.

* * *

Even with the help of T.V., the task before Tsongas is not easy. The congressman is already fairly well known in Cambridge and the surrounding area, having served as a Middlesex County commissioner before entering Congress. Still, to ensure that no one has forgotten his name and his past accomplishments, Tsongas spent an afternoon in Cambridge, Somerville, Arlington and Belmont several weeks ago. His experiences that day, although not typical, provide a good idea of the difficulties Tsongas faces in his battle to increase his name recognition.

After a brief stop at the offices of the Cambridge Chronicle, Tsongas, accompanied by Goldman and Charles Zgonis, Tsongas's campaign coordinator in the Cambridge area, arrived at Cambridge City Hall five minutes late. Their first stop was the office of city manager James L. Sullivan.

"You got my vote," Sullivan told Tsongas. But this declaration did not boost Tsongas's hopes much--the two men are already good friends, dating back to the days when Tsongas was a Lowell City Councilor and Sullivan was Lowell city manager, so the endorsement was expected.

Sullivan took the candidate on a tour of most of the city offices. "How you doing, Paul Tsongas, running for United States Senate," Tsongas repeated to every tax collector, auditor, clerk and secretary he met, always placing the accent on his name. The reactions he received ranged from disinterested nods to an embrace and kiss from one secretary; that seemed to ensure him one vote at least, but the stop could not be considered a complete success. Several city councilors who were supposed to meet with Tsongas were not around.

Just as Tsongas was leaving City Hall he was already expected at Somerville City Hall--and he still had to make an interview scheduled at radio station WCAS in Central Square before he could go anywhere else.

At Somerville City Hall, as he had in Cambridge, Tsongas toured all the offices but again encountered bad luck: the mayor was not in. The only bright spot during this stop came on the way to Somerville, when a policeman generously did not pull over the campaign car after it made an illegal U-turn in front of him.

* * *

The WCAS interview was one of the few chances Tsongas had during the day to discuss issues. Fielding a question on his stand on nuclear energy, Tsongas replied that he favors using light water reactors, the type being built at Seabrook, N.H., because he believes the energy alternative--coal-- is worse. Even though the problem of how to dispose of the radioactive waste from such reactors has not been solved, Tsongas said using coal to replace the 30 per cent of total energy now supplied by nuclear power would be disastrous, raising the chance that it could bring about harmful climactic changes.