Boston — Democratic presidential candidates are moving about New England with increasing frequency as they try to stake out political turf. The routes to New Hampshire, scene of the traditional first-in-the-nation primary late next winter, are particularly well traveled. The six Democratic aspirants have not only visited the Granite State several times, their campaign organizations have set up shop there, too. So far few of New Hampshire's more prominent Democratic Party activists have lined up behind a candidate.
In nearby Massachusetts, however, the endorsement parade is well under way. Seven of the 12 Democratic members of the Massachusetts congressional delegation , including Sen. Paul E. Tsongas, have formally taken sides. So have two of the state's so-called constitutional officers - Attorney General Francis X. Bellotti and Secretary of State Michael -Joseph Connolly - and the leaders of both state legislative chambers.
Former Vice-President Walter F. Mondale, for example, has the declared support of US Reps. Edward P. Boland, Joseph D. Early, Barney Frank, and James M. Shannon, plus Secretary Connolly and state House Speaker Thomas W. McGee.
Sen. John Glenn of Ohio, besides having the endorsements of Senator Tsongas and Attorney General Bellotti, has the backing of US Reps. Brian Donnelly and Nicholas Mavroules, state Senate President William M. Bulger, and Senate majority leader Daniel J. Foley.
Particularly prominent in the Massachusetts campaign for Sen. Alan Cranston of California is his state coordinator, Thaleia Schlesinger. She is Senator Tsongas's twin sister.
Several other prominent Massachusetts Democrats are also expected to endorse a presidential candidate soon. Gov. Michael S. Dukakis, who has been visited by at least five of the six hopefuls in recent months, says he will announce his preference this fall.
Meanwhile, in New Hampshire, state Democratic chairman George Bruno says he has no intention of abandoning his neutrality in the presidential campaign until after the primary.
Mondale supporters in the Granite State include former state party chief Romeo Dorval.
J. Joseph Grandmaison of Nashua, the 1976 Democratic nominee in the state's Second Congressional District, is national political director of the Glenn campaign. Meanwhile, Mr. Grandmaison's brother, Philip, is Granite State coordinator of the Cranston organization.
Former Florida Gov. Reubin Askew, Colorado Sen. Gary Hart, and South Carolina Sen. Ernest Hollings also won some endorsements.
Although the New Hampshire primary is still more than six months off, each of the six contenders has been there at least once within the past two weeks.
Moreover, the exact date of the primary is still in dispute. National Democratic Party rules require that the balloting take place no earlier than March 6. New Hampshire's secretary of state, however, insists that it must be held Feb. 28, since state law specifies the vote must come at least a week before any similar vote in another state. Vermont has scheduled its so-called ''beauty contest,'' or nonbinding presidential primary, for March 6. Efforts to resolve the dispute rules are continuing.
Maine Democrats also have a scheduling problem. State law sets March 4 for the city and town party caucuses at which delegates committed to presidential candidates will be chosen, at least indirectly. Yet the national party forbids such activities before March 13, except for the Iowa caucus in late February and the New Hampshire primary.
Party leaders met with Democratic national chairman Charles Manatt in late July but were unsuccessful in winning support for an earlier caucus. Another try will be made in September before the Democratic Compliance Review Committee, in Washington.
Both Maine and Vermont have been included in Democratic presidential campaign swings in recent months, although to a lesser extent than New Hampshire. Considerably less activity has surfaced in either Rhode Island or Connecticut.