SACRAMENTO -- Though a formal prediction isn't out yet, officials and analysts said Wednesday they expect a low voter turnout for next week's election, which would endanger the $12.3 billion school bond but could help Gov. Arnold Schwarzenegger's $15 billion deficit bond.

Experts are predicting a statewide turnout percentage for Tuesday's presidential primary in the high 30s to low 40s -- less than the October 2003 gubernatorial recall election, in which 43 percent of eligible voters cast ballots, and more on par with the 37 percent who voted in March 2000.

Bay Area election officials made similar forecasts.

"I don't think we'll get over 50 percent," said Alameda County Registrar of Voters Brad Clark.

That figure would be down from the March 2000 presidential primary when voters were narrowing replacement choices for President Clinton and the county logged a turnout of 53.8 percent.

"Turnout is related to the excitement and interest generated by an election," said Tim Hodson, director of the Center for California Studies at California State University, Sacramento. "And the Democratic presidential nomination contest is largely over."

"Although some of the ballot measures are incredibly important to the future of the state, none have really caught the popular imagination," Hodson said.

Likewise, the U.S. Senate race isn't drawing much attention, with Sen. Barbara Boxer unopposed for the Democratic nomination and a large field of Republican candidates running for the chance to oppose her in the November general election.

Though there's a sprinkling of hotly contested congressional and legislative races across the state, analysts said it won't be enough to generally boost turnout.

Other factors, experts said, include the limited role independents can play now with the erosion of California's open-primary system and the fact presidential primary election turnouts historically fall far below those for November general-election runoffs.

Pollsters said turnout will play a bigger role in the outcome of weighty school and deficit bond measures with surveys showing voter support levels hovering near the 50 percent majority needed to pass the measures.

In particular, "voter preferences on Proposition 55 (the school bond) are directly related to the age and race of the voters," according to Mark DiCamillo of the Field Poll.

Analysts expect the most reliable voters -- who tend to be older, Republican and conservative -- to lean toward the GOP governor's Proposition 57 deficit bond and against the Proposition 55 school construction bond.

They said the less dependable voters are the generally younger and more plentiful Democrats, who would tend to support the school bond and are split over the deficit bond.

In a Field Poll released Tuesday, the Proposition 55 school bond was backed by 51 percent of likely voters, with 40 percent opposed and 9 percent undecided.

The Proposition 57 deficit bond was favored by 50 percent and opposed by 36 percent, with 14 percent undecided. And the companion, balanced-budget measure -- Proposition 58 -- was backed by 55 percent, with 28 percent opposed and 17 percent undecided.

There's a "skeptical uncertainty" about the deficit bond among voters, particularly Democrats in the Bay Area, said Mark Baldassare, director of the Public Policy Institute of California poll.

They have "real misgivings about doing anything that will put the state further into debt," Baldassare said.

Republicans are supporting the Proposition 57 deficit bond by a more than 2-1 ratio, the Field Poll found, while Democrats and independents are almost evenly divided over it.

At the same time, on the Proposition 55 school bond, "support is strongest among younger voters and among racial and ethnic minorities," DiCamillo said.

"On the other hand, voters over age 65 oppose the school bonds initiative 52 percent to 36 percent and white non-Hispanics are evenly divided," he said.

Meanwhile, analysts said, a low turnout -- in which there's a lackluster Democratic turnout -- also is expected to further hurt Proposition 56, a measure that would allow the Democrat-dominated Legislature to pass a budget and tax hikes on a 55 percent vote rather than the current two-thirds margin.

Already, the latest Field Poll has indicated that 51 percent of voters oppose the measure and 33 percent favor it, with 16 percent undecided.

"While Democrats are about evenly divided on Proposition 56, Republicans are strongly on the no side, opposing the initiative 64 percent to 24 percent," according to DiCamillo. "Non-partisans are also against it, 52 percent to 29 percent."

The low voter turnout prediction comes despite a recent plea by the state's top elections official, Kevin Shelley.

"Not only are there important statewide propositions and candidates on the ballot, but voters will have the unique opportunity to affect our national agenda by selecting a presidential nominee," he said.