The Massachusetts democratic gubernatorial campaign looks much the same now as it appeared during the first six months of political stumping. Two independent polls showed former Gov. Michael Dukakis comfortably in the lead, claiming 50 to 70 percent of the vote. Gov. Edward J. King still trails, with one-third to one-fourth of those polled backing him, while Lt. Gov. Thomas P.O'Neill III is edging out "undecided" voters for a distant third place.

But all three camps concede the extreme volatility of those figures with the primary still five months away.

The next date marked on the political calendar is April 20, when the candidates will square off for the first time in a televised debate arranged after weeks of squabbling over format and content.

O'Neill, who most observers say has most to gain from the debate, has already cut down on campaign trips around the state, and is currently devoting two hours a day to briefings. King is planning a short vacation later this week to begin strategy sessions.

But the debate, which will focus on taxation and public expenditures, is only one of several outlets for the intensifying efforts to target specific groups and areas.

King last week sent out mailings to several thousand lawyers around the state, reminding them of his commitment to an improved legal system and of the number of judicial appointments he has made during the last three years. Dukakis has started a series of discussions with municipal employees in several towns, meeting with policemen and firemen concerned with the effects of layoffs.

And all three democratic candidates are now wooing local government officials. At a meeting of the Massachusetts Municipal Association on March 27, the three candidates appeared separately to present their respective proposals for local aid. The governor announced a plan for $100 million devoted to cities and towns in his proposed budget, now before the legislation. The two challengers, appearing after King, sharply criticized his promises.

"For the past three years Massachusetts has been lurching from one crisis to the next, while state government ran on automatic pilot," Dukakis said before reiterating his own plan to commit 40 percent of all state revenue growth to local aid.