'I ask you to stand with us in this election.'

LOWELL -- Lieutenant Governor Kerry Healey accepted the state Republican Party's official endorsement for governor yesterday with a sharply partisan speech, blasting two leading Democratic rivals and warning that one-party rule by the Democrats would bring tax hikes.

Healey, who was unopposed for the GOP nomination, used the state party convention to pillory Attorney General Thomas F. Reilly as a ''flip-flopping . . . political chameleon" and to paint another potential Democratic rival, Deval L. Patrick, as a ''big-spending" liberal who can't be trusted not to raise taxes.

''Who can argue with a straight face that [Democrats] do not already have enough power as it is?" Healey said in her speech accepting the nomination. ''To every voter who wants to keep two-party democracy alive in this state and hold your government accountable, I ask you to stand with us in this election."

Healey's speech highlighted one of the most subdued Republican conventions in memory, and it came after the convention endorsed a GOP ticket of little-known and underfinanced candidates for the other statewide offices. With the exception of her running mate, former state representative Reed V. Hillman, the other candidates have little political experience or financial resources.

Though she was received warmly at the convention, Healey's primary audience was far from the Tsongas Arena yesterday.

With only 13 percent of the state's voters registered as Republicans, Healey will have to draw on her socially moderate, fiscally conservative views to win over independent voters, who make up roughly half the state's electorate. Much as Governor Mitt Romney rode support from independents into the corner office in 2002, Healey is reaching out to largely suburban voters -- high-tech workers along Interstate 495, the ''soccer moms and dads" on the North and South shores -- fearful of more Democratic dominance.

In his 2002 campaign, Romney successfully painted Democrat Shannon O'Brien as a Beacon Hill insider. Four years later, Romney sounded a similar theme.

''The Commonwealth of Massachusetts would make a huge mistake and a big step backward by not having two parties on Beacon Hill," Romney said yesterday.

Romney, whose reception by the crowd was muted compared with the rousing reception he got at the 2002 convention, called on activists to rally behind Healey. He described himself as ''personally prolife" last year, while Healey has distanced herself from his conservative stances and his style of governing. She appeared at an GOP abortion-rights gathering yesterday after the convention.

The governor, in a press conference yesterday, said it was a ''necessity" for Healey to cut her own path. ''I think everyone who runs for office is going to define themselves by their own views and their own positions, and that's precisely what she's doing," Romney said. ''That's what the people expect."

In her speech to some 2,500 activists at the Paul E. Tsongas Arena, Healey repeatedly hit on what has become her major campaign theme: that fiscal restraint, antitax activism, and business-friendly policies long advocated by Massachusetts Republicans would evaporate on Beacon Hill if the GOP loses the governor's office.

''Facing a party with too much power already, we have held the corner office as a last line of defense against their worst instincts," Healey said. ''Yet sometimes the other party speaks as if that office were theirs by right and we should step aside and spare them the trouble of elections."

Healey chided Reilly for pushing legislation to provide in-state tuition rates for children of undocumented immigrants, and she boasted that she and Romney had forced the Democratic Legislature to back off its attempts to weaken the drunken driving legislation known as Melanie's Bill.

''Moments like these are previews of what single-party rule in this state would be like," Healey said.

She portrayed Reilly as a political insider who, as a career prosecutor, had worked within the political establishment and allied himself with those who finance it. Healey accused Reilly of ''making all the right insider connections, pandering to all the right groups, and waiting in line for your turn."

''But after a while, the act wears pretty thin," she said. ''You can serve the special interests or you can serve the public interest. Tom Reilly has made his choice and I have a feeling he's going to pay the price when the voters make theirs."

Healey said that Patrick is a committed liberal who wants to grow state government.

''I guess you could say that candor from a committed liberal like Deval Patrick is better than the flip-flopping of a political chameleon like Tom Reilly," Healey said, adding that the attorney general is ''suddenly on board" with her call to roll the income tax rate back from 5.3 to 5 percent. She did not mention Chris Gabrieli, the third Democratic candidate.

Corey Welford, Reilly's spokesman, said Healey's attack on the Democratic candidates was ''pathetic" and was aimed at covering up the Romney administration's lackluster record on job growth and rising cost of living. ''She's just reverting to a playbook of misleading voters and attacking," Welford said.

Patrick's campaign declined to directly respond to her attack, choosing instead to reiterate his call for what he describes as a ''fiscally responsible tax policy, a streamlined and efficient state government, and a renewed commitment to important priorities like education, healthcare, and our cities and towns."

In a statement, Gabrieli said, ''without fail, every four years Republican candidates for governor tell us balanced government alone is the most important thing. But what use is balance if the only result we get is stagnation?"

Republicans expect Healey, whose husband has a huge personal fortune, to help finance a campaign against Democrats desperately trying to regain the corner office after 16 years. Her task is complicated by Christy Mihos, a former Republican who is running as an independent.

State Representative Karyn E. Polito, a Shrewsbury Republican and convention delegate, said yesterday that the threat of Democratic dominance will help Healey capture independents out in her district.

Some delegates complained about Healey's liberal stances. Chris Noonan Funnell and her husband, David Funnell of Uxbridge, wore red tape over their mouths with ''LIFE" written in black capital letters to protest Healey's support for abortion rights.

The only contested endorsement was for the party's nomination to run against US Senator Edward M. Kennedy. Ken Chase, an educator from Belmont, won the endorsement over Kevin Scott, a businessman from Wakefield. The two will face off in the state primary election on Sept. 19.

The party convention endorsed Lawrence Frisoli, a Cambridge lawyer and one-term city councilor, for attorney general; Earle Stroll, a business consultant from Harvard, for state auditor; and Ron Davy, a one-term Hull selectman and financial analyst, for state treasurer. The party has no candidate running for secretary of state.

As Davy was finishing his speech yesterday, Dennis Shank, a 56-year-old convention delegate from Lawrence, walked by the press table and said, ''I would rather have Abe Lincoln as he is today -- dead on the five dollar bill -- than whoever that guy is up there."

''There's nobody to vote for this year," Shank added. ''Nobody."

Former US senator Edward Brooke also lamented the state of the Republican Party in his speech to the convention. The crowd was hushed as Brooke, 86, listed each state and federal elected office and noted how few Republicans could be found there.

Said Brooke: ''We've got to go back to the grass roots where we started from and rebuild this party." His remarks drew a standing ovation.

Globe correspondent Michael Naughton contributed to this report.