Massachusetts state elections are still a year away, but Republican candidates are already looking to 1990 as their best chance in decades to steal major state offices from the seemingly invincible Massachusetts Democratic Party.

Republican candidates for governor, lieutenant governor and other key offices are optimistic that the new decade could end an era in which their party has played a small role. Democrats, on the other hand, are fighting to save their reputations--tarnished by the state's fiscal crisis--and preserve a 20-year rule on Beacon Hill.

Candidates say this upped ante in the races next year has started the election cycle off earlier than usual.

"Nineteen-ninety is going to be an amazing political year in Massachusetts," says Rep. Stephen D. Pierce (R-Westfield), House minority leader and a frontrunner in the Republican primary for governor. "This gubernatorial cycle has kicked off earlier and with more intensity than before."

"It's indicative of what's at stake in the state," Pierce adds.

NEXT November, 277 state, county and federal offices will be up for grabs in Massachusetts, and Republicans say they expect to have a candidate seeking every one. Two years ago, the GOP ran in less than 50 percent of the races.

Early next year, both parties will hold conventions to endorse candidates and eliminate those with little support. And because of what they see as brighter prospects in 1990, the competition has already begun among Republicans, whose non-binding convention will endorse one candidate in each of the 277 races.

Five Republican candidates have begun raising money for campaigns for governor--a position that has not been won by their party since 1972. Although so far they have not generated the amount of campaign money their Democratic counterparts have, they have a number of other advantages.

The most obvious of these is the $500 million deficit in the state budget, which many have blamed on the Democratic leadership, led by Gov. Michael S. Dukakis and House Speaker George Keverian '53 (D-Everett).

Republicans charge that the administration could have avoided the crisis if it had heeded warnings put forth by Republican representatives.

"Indeed, in some instances, [the Republicans] were correct," says Rep. John Flood (D-Canton), a candidate for governor and chair of the Taxation Committee. He says he has voiced his opposition to the Democrats' budget plans since they were first debated.

Many voters in Massachusetts--now paying the first installments of an emergency increase in the state income tax of three-quarters of 1 percent--may not approve of a $855 million tax package to cover the deficit, under consideration in the Democrat controlled House of Representatives.

"If they had heeded some of the things I had said, they could have avoided this situation," says Pierce, who advocates cutting "unnecessary" spending to curb the deficit instead of new taxes.

"We have to bring Massachusetts state spending in line with our existing resources," Pierce says. "Massachusetts taxpayers cannot be responsible for flitting the bill for mismanagement."

Another advantage is a split among leading Democrats over how best to remedy this situation. Republicans say that instead they are concentrating their forces on the campaign year ahead.