Rep. Boxer Will Run for Cranston’s Senate Seat : Politics: Marin County Democrat moves up planned announcement after senator said he would not seek reelection. She joins Congressman Robert Matsui as a candidate.

One day after Sen. Alan Cranston (D-Calif.) announced he would not seek reelection, Democrat Barbara Boxer, a congresswoman from Marin County, declared Friday her candidacy for one of the two California Senate seats to be contested in 1992.

Boxer, 49, who has been raising money and considering a challenge of Cranston all year, had planned to announce her candidacy in January. But she said she moved up her timetable because of Cranston’s announcement Thursday that he would not run because he has prostate cancer.

“I felt it was important to state my intentions now,� Boxer said.

She joins Rep. Robert T. Matsui (D-Sacramento), also 49, as declared contenders for Cranston’s seat. Matsui has said he intends to run but will not make a formal announcement until later. Boxer’s announcement was seen by political insiders as an attempt to stake out the left-of-center turf in the June, 1992, Democratic primary.

“I will be running based on issues of the environment, a world of peace, economic prosperity, individual freedom of choice (on abortion) and freedom of the arts,� she said. “I want to get to the Senate and be a fighter for the people.�

On Thursday, Boxer was unavailable to comment on Cranston’s decision, but issued a brief statement expressing concern about his health. Friday, she and campaign director Ed McGovern began calling political reporters to announce her decision.

“I want to change the face of politics in California,� she said in a telephone interview from San Francisco. “I want to have a campaign that touches the people and gets them excited and involved. It’s going to be a people-to-people campaign because that’s what I do best.�

Democratic political experts have said the potential Senate candidacy of Dianne Feinstein, who narrowly lost the governor’s race to Republican Pete Wilson on Tuesday, could lessen Boxer’s chances. By pitting two San Francisco Bay Area women against each other, Feinstein would hold a clear edge in statewide visibility and fund-raising ability.

But Boxer said: “I’ve always said that no matter who would run, it was irrelevant to my candidacy. I made the decision not based on anyone else.�

Boxer said she planned to raise about $4 million for the 1992 primary campaign. She has collected about $850,000 so far this year, she said.

Boxer was a Marin County supervisor for six years before winning the 6th Congressional District seat in 1982. She was reelected by a margin of more than 2 to 1 Tuesday. The seat covers portions of San Francisco, Marin, Sonoma and Solano counties. She is on the House Budget and Government Operations committees, but leaves the Budget Committee in January and returns to the House Armed Services Committee.

Boxer has been an active member of the congressional military reform caucus in the House, a leading proponent of abortion rights and a foe of offshore oil drilling. The “Almanac of American Politics� describes Boxer as “a team player, a member usually loyal to the Democratic leadership, to feminist causes, to caucus groups representing significant constituencies in her district and a good pol.�

Matsui, a member of the House Ways and Means Committee, won attention in recent years for his sponsorship of legislation to provide an official apology and monetary reparations to Japanese-American citizens who were interned in camps during World War II. Matsui was in a camp as an infant.

Matsui, an effective fund-raiser, said he believes he has an advantage in representing inland California. “I don’t think a Democrat can win the state unless they win the Central Valley of California. That’s my base,� he said.

Other potential Democratic candidates are Rep. Mel Levine of Santa Monica, former Gov. Edmund G. Brown Jr., Lt. Gov. Leo T. McCarthy, Controller Gray Davis and Walt Disney Corp. President Frank Wells.

This will be the first time Cranston’s Senate seat will be open--with no incumbent seeking reelection--since 1950, when Sen. Sheridan Downey retired and the seat was won by Richard M. Nixon.

But California’s other Senate seat also will be at stake in 1992. Wilson will resign from the Senate to take office as governor. He will appoint a successor who will serve through the 1992 general election.

Most Republicans are waiting to see who Wilson picks before beginning the formal jockeying for the Senate positions.