SACRAMENTO - A Field Poll released today shows that Democratic candidates are leading in each of the half-dozen "down ballot'' races in November, with Oakland Mayor Jerry Brown holding a substantial lead in his bid for attorney general.

Even incumbent Republican Secretary of State Bruce McPherson, from Santa Cruz, trails -- though his battle with state Sen. Debra Bowen, D-Redondo Beach, is the closest contest.

The poll, taken July 10-23, reveals that as many as 25 percent of the voters are undecided in some races and that many of the candidates are not well-known.

But two that are -- Brown and current Attorney General Bill Lockyer -- have the biggest leads.

Brown leads state Sen. Charles Poochigian of Fresno 54 to 33 percent, but just 16 percent of voters said they even have an opinion of Poochigian. Nearly one quarter of Republicans said they would vote for Brown, the former governor and presidential candidate.

Lockyer has a 52-27 spread over Board of Equalization member Claude Parrish in their race for treasurer. But only 14 percent of voters have an opinion of Parrish.

The Democrats with the most tenuous leads are Bowen and current Lt. Gov. Cruz Bustamante, who was defeated soundly in the recall election that swept Gov. Arnold Schwarzenegger into office.

Bustamante has just a 43-39 lead over Bay Area businessman Steve Poizner in the race for insurance commissioner, despite just 15 percent of voters having an opinion of Poizner.

Bowen holds a slight lead over McPherson, the lone Republican down-ballot incumbent, though he is not widely known either, with 72 percent having no opinion of him. She leads McPherson 38-35, but 26 percent are undecided.

In other races, current Insurance Commissioner John Garamendi, a Democrat, has a 48-38 lead over Republican state Sen. Tom McClintock of Thousand Oaks for lieutenant governor; and Board of Equalization member John Chiang, a Democrat, has a 38-27 lead over former Republican Assemblyman Tony Strickland of Moorpark in the state controller's race, though 34 percent are undecided.

The margin of error was 5.2 percentage points.