Hayden in Tight Contest for New 23rd District Seat : State Senate: Longtime assemblyman struggles in his bid for the upper chamber. In the 25th District, Teresa Hughes took a large lead.

In an up or out contest, Assemblyman Tom Hayden struggled in his fight for political survival Tuesday against a veteran incumbent and a public relations consultant in a tight Democratic race for a new state Senate district that stretches from the Westside to the San Fernando Valley.

Hayden, 52, who has cast himself as an outsider since his days as an anti-war protester during the Vietnam era, chose to challenge fellow liberal Sen. Herschel Rosenthal of Los Angeles for a four-year term in the new 23rd District rather than seek reelection in his redrawn Santa Monica-based Assembly district.

The costly race also featured Catherine O’Neill, 49, who drew national attention last winter as a leader of the highly charged effort to overturn the award of a $121.8-million Metro Green Line contract to the Japan-based Sumitomo Corp. In 1972, she lost an election that would have made her the first woman state senator in California.

In an exceedingly slow count of ballots, Rosenthal took a substantial early lead over Hayden and O’Neill, but as returns mounted, Hayden seemed to be closing the gap. Hayden’s campaign manager said the candidate, who secluded himself with supporters during the long night, was encouraged by late returns.

Winning the Democratic primary is tantamount to capturing the four-year seat in the November general election because no Republican entered the race.

Hayden, who was elected to the Assembly a decade ago, bankrolled his Senate campaign with more than $700,000 of his own money and that of his political organization, Campaign California. Rosenthal, 74-year-old dean of an influential Westside political organization, conducted a lethargic reelection effort.

The Hayden-Rosenthal-O’Neill race was the premier contest in primaries for 20 seats in the 40-member Senate. These included spirited fights over seats vacated by retiring veterans Bill Greene, a Democrat whose district covers much of riot-scarred South Los Angeles, and Republican Ed Davis of Santa Clarita, a former Los Angeles police chief.

In the election to succeed Greene in the 25th District, Assemblywoman Teresa Hughes, a 17-year member of the lower chamber and former aide to Rep. Mervyn M. Dymally, took a major lead over opponent Paul H. Richards. She ran with the support of most Democrats in the Senate. Greene, however, endorsed Richards, a Lynwood city councilman, as did Dymally. Richards attacked Hughes as a carpetbagger for moving into Inglewood to run for the Senate.

In an exceptionally nasty Republican campaign, Assemblywoman Cathie Wright of Simi Valley jumped off to a narrow lead over retired Assemblywoman Marian LaFollette, who sought to make a political comeback by succeeding Davis in the heavily GOP 19th District that reaches from the northwest San Fernando Valley to Oxnard in Ventura County. Although disappointed by early returns, LaFollette said, “I feel like I’m still in the race.”

To the south, two other Assembly Republicans, Carol Bentley of Santee and David G. Kelley of Idyllwild, fought it out to represent the newly created 37th District that includes parts of San Diego, Riverside and Imperial counties. Taking a substantial lead in returns, Kelley fought hard for name recognition in vote-heavy San Diego while Bentley was given the edge on fund raising.

In the north, 71-year-old Sen. Milton Marks (D-San Francisco), who first was elected to the Assembly in 1958, trounced former San Francisco Dist. Atty. Joseph Freitas. The newly realigned 3rd District stretches from San Francisco across the Golden Gate to bedroom communities in Marin and Sonoma counties.

Most Senate incumbents were unopposed in the primary and will face opposition only in November. In addition to Rosenthal and Marks, other incumbents with at least token primary opposition included Sens. Becky Morgan (R-Los Altos Hills), Henry J. Mello (D-Watsonville), Robert G. Beverly (R--Manhattan Beach) and John Lewis (R-Orange).

Contributing to this story were Times staff writers Gerald Faris, Carlos Lozano, Patrick McDonnell and Jeffrey Rabin and correspondent Jeanette Avent.