Saying that "I resent and reject" the suggestion that he is "less American" than President Carter, Sen. Edward M. Kennedy (D-Mass.) vowed today to continue his presidential campaign no matter what the results of Sunday's Maine Democratic town caucuses.

Kennedy, who said immediately after his loss to Carter in Iowa that a victory in Maine is essential, came back here for a final bit of campaigning with the declaration that his candidacy will not be tested fully until Carter leaves the White House and meets him in debate.

Kennedy visited three communities this afternoon, and is coming back Sunday to tour three of the sites where Democrats will elect delegates to the state convention. The 22 Maine national convention delegates will be apportioned according to Sunday's result.

At a news conference here, Gov. Joseph E. Brennan and ex-senator William Hathaway, Kennedy's principal backers, predicted victory. But Kennedy said only that he hoped to "do well."

He expressed strong resentment of the Carter radio and television ads, using excerpts from the president's State of the Union address, and an announcer's voice urging voters to "stand up and be counted for Maine and America" by supporting Carter at the caucuses.

"I suppose I resent -- and I hope the people of Maine resent -- the suggestion that anyone who challenges the policies of this administration . . . does not stand up for America," Kennedy said. "I resent and reject this suggestion that . . . that we have to accept without discussion and debate the record of the last three and a half years are less American than those who hold some office today . . ."

Kennedy's personal campaigning was part of a last-minute blitz aimed at averting the predicted defeat in Sunday's caucuses. The most recent public poll, published Friday by The Bangor Daily News, gave Carter a 52.4-33.4 percent lead among registered Democrats.

California Gov. Edmund G. (Jerry) Brown Jr., who had 5.1 percent in the poll, completed a week's barnstorming today.

Kennedy today flooded the city with more than 1,000 workers, half of them out-of-state student volunteers who were bused up Friday night and stayed in armories here and in Augusta.

A Carter coordinator here, watching the Kennedy canvassers fan out from the downtown hotel headquarters, said "There are more canvassers in Portland this week than there were caucus voters in 1976" -- and only 6,800 Democrats in the whole state participated.

Estimates are that as many as three times that number will vote Sunday, but even so, the ratio of campaign workers to voters is probably as high as it has ever been in a presidential contest.

The Carter organization, which relied chiefly on telephone canvassing, deployed fewer foot soldiers today, but between the two campaigns there will probably be a worker for every eight to ten voters.