Democrats' extravaganza, as seen from living rooms across the US

Each night this week, the Democratic Party has been displaying its wares to prime-time TV audiences around the country. Are Americans buying? Monitor reporters fanned out to see what effect the San Francisco convention had on voters, paying special attention to members of the broad coalition the party must mobilize to win in November.

Prominent New England Democrats who watched the convention from back home appear generally pleased with what they saw and heard, especially the speeches. But they were anything but unanimous in their assessments of its effect.

''It was the most upbeat convention I've seen,'' enthused state Rep. Charles F. Flaherty Jr. of Cambridge, a one-time Massachusetts Democratic chairman, who was a delegate to the party's the 1972 and 1976 conventions.

''I was never more proud of being a Democrat,'' New Hampshire executive councillor Dudley Dudley said in assessing the convention, which was the first she had missed attending since 1968. The speeches by New York Gov. Mario Cuomo and candidates Jesse Jackson and Gary Hart ''were outstanding, and reflected the diverse strengths of our party,'' she added.

As Boston City Council president Joseph M. Tierney viewed it, the lengthy nominating procedure Wednesday night ''certainly was not exciting. Personally I find Walter Mondale about as exciting as a melted popsicle,'' he said. But he continued, ''Now it is time to push together and hope for a Democratic victory'' in November.

Connecticut Lt. Gov. Joseph Fauliso hailed the convention as ''electrifying'' and ''great for our party.'' Walter Mondale and Geraldine Ferraro ''are a strong ticket,'' he emphasized.

Quite a different assessment of the convention was voiced by state Rep. Saundra Graham of Cambridge, Mass., a longtime black activist, who said she ''did not get the feeling there was real unity. ... I sensed there still are a lot of hard feelings.''

She was less than enthusiastic over the Mondale nomination. ''I don't feel the black community got anything,'' she said. ''Walter Mondale has got to do a lot more reaching out to blacks and other groups.''

David McKellar, Maine Democratic Party treasurer, described the convention as ''splendid'' and ''setting the tone for a strong campaign.''