AUGUSTA – They are, in many ways, opponents whose distinctions are eclipsed by their similarities.

Both are former Republican legislators and fiscal conservatives who believe state government must be reined in. They support tax reform, increased health care accessibility and the expansion of educational opportunities.

And when the polls close Tuesday, either Peter Cianchette of South Portland or James Libby of Buxton will carry the party’s standard against the Democrats, w ho want to regain the governorship after a 16-year banishment.

A number of GOP election watchers agreed Friday that the few issues on which the candidates disagree, their comparative campaign styles, television ads, personal appeal and differing backgrounds will influence Republicans only marginally as they march to the ballot box. Instead, the bottom line for many GOP voters will be which of the two they think can beat the Democratic candidate, U.S. Rep. John Baldacci, who continues to hold a significant lead over all challengers in every state poll commissioned to date.

Voter turnout, according to Patrick Murphy of Strategic Marketing Services in Portland, is expected to be no more than 30 percent of Maine’s 272,450 Republicans. Turnout is expected to be higher in the 2nd Congressional District, home to 126,450 Republicans, than in the 1st District, where GOP voters are slightly more numerous at 146,000.

Scott Fish, a conservative Dixmont Republican who owns the As Maine Goes commentary Web site, believes the turnout will be higher in the 2nd District because of the flurry of interest in that district’s four-way GOP congressional primary race. Still, Murphy cautioned the statewide average for GOP turnout could be as low as 25 percent.

Another factor driving the outcome of the Republican gubernatorial primary is advertising and the means to pay for it. Each candidate has invested about $225,000 in broadcast and print media to get his message out to Republicans.

Cianchette, a businessman-turned-consultant, is running a privately funded campaign and had spent a little more than $431,000 as of May 30. Libby is a publicly funded candidate under Maine’s Clean Elections Act and had spent nearly all of the $328,000 he was eligible to receive by the May 30 campaign finance filing deadline.

Abby Holman, executive director of the Maine Forest Products Council and an avid observer of GOP politics, agreed with Murphy’s assessment that somewhere between 15 percent and 20 percent of all Republicans had yet to make up their minds about who to vote for and that the heavy rotation of ads pummeling voters this weekend will have some effect. Each candidate has produced three ads that are largely introductory and biographical, although both have emphasized a need to revitalize the economy. Libby, a 41-year-old high school teacher, also has employed educational themes in tandem with his economic message.

“Television is going to make a difference,” Holman said. “Because the people who are most likely to vote will have been influenced by those ads.”

The ability of each candidate to sustain financially a credible campaign also may be a factor in the minds of some Republicans. Should Libby win the primary, he would be eligible for another $860,000 in taxpayer-provided campaign funds for the general election.

But Fish and others wondered if that would be enough – particularly when considering that Baldacci of Bangor, who doesn’t even have a primary opponent, already had raised $717,000 and spent $679,000 as of May 30. Jonathan Carter, the Green Independent Party candidate from Lexington Township, also is publicly funded with a guaranteed campaign war chest equal to Libby’s. David Flanagan, a Manchester independent who happens to be independently wealthy, has written himself personal checks to cover most of the $537,000 in expenses incurred by his campaign through May 30. State Rep. John Michael, an Auburn independent, is the most recent addition to the gubernatorial ballot, but he has yet to amass any significant funding.

The Libby campaign countered Friday that $860,000 is more than enough to run a winning campaign through November, adding that those who spend more may be perceived as trying to buy the election and may lose valuable campaign time to raise funds.

The funding issue has provided one of the few areas of contrast between Libby and Cianchette. After biting his tongue on a few occasions, Cianchette, 40, unloaded on Libby at the Republican State Convention for relying on Maine taxpayers to fund his campaign. He did this, he said, after Libby’s repeated not-so-vague insinuations that private campaign contributors more or less get what they pay for. The most recent example of that mild sniping was aired on a Maine Public Broadcasting Corp. candidates’ forum last month. Libby was responding to Cianchette, who said he was offended by his opponent’s decision to run as a publicly funded candidate when the state was facing serious financial difficulties.

Libby countered that the real financial problems stemmed from special-interest groups exerting their influence in the State House.

“That money must be buying something,” Libby said.

To a lesser degree, Republicans may be convinced that Libby is the more conservative of the two candidates while Cianchette is more moderate. Yet there is little actual evidence to support either perception. Both men oppose late-term abortions, but neither supports overturning the landmark Roe v. Wade decision legalizing abortion on demand. Libby actually does oppose laws that would grant civil rights protections to homosexuals, while Cianchette promises he would not veto a bill ensuring those benefits should the legislation reach his desk.

Holman asks: Does it really matter?

“I don’t know how much impact that one issue will have,” she said. “I just don’t think it’s necessarily a defining issue for that many Republicans.”

The Libby campaign apparently disagrees. Libby has invested heavily in advertising on radio stations that are Christian-themed and are staunch opponents of gay rights laws. With a one-time advertising buy of $27,000 in Aroostook County, where opposition to gay rights apparently is more entrenched than in the rest of the state, Libby has outspent Cianchette by about an 8-1 ratio.

According to statistics on the Secretary of State’s Web site, 51 percent of voters statewide voted in 1998 to repeal a gay rights law passed by the Legislature the previous year. In Aroostook County, 74 percent of voters supported the repeal.

That means “Libby for Governor” signs should be sprouting up in Aroostook County like potato blossoms in July. Not so, according to Craig Green of Presque Isle, who is chairman of the Aroostook County Republican Party.

“My gut feeling is that that’s probably not the case,” said Green, who added he had not yet committed himself to a candidate. “When it comes to people coming to me to get involved in a campaign, they’ve almost entirely all been for Cianchette. They think he’s the candidate who can beat Baldacci in November.”

But Ben Gilman, Libby’s campaign manager, counters that Libby “can beat Baldacci because he’s going to draw votes from Democrats.” He said no candidate works harder than Libby. “And with this crowded field of five candidates, he’s not going to need 50 percent to win this election in the fall.”