LOS ANGELES -- The campaign commercial begins with a loud, terrifying "CRASH!"

A ship's alarm wails. The oil tanker Exxon Valdez wallows on a reef. A dead otter covered with oil is pulled from Alaskan muck. Actor James Garner appears and says, "Now that the world is waking up to the environmental threat, corporate polluters and politicians are spending millions to turn back the clock."

A newcomer to the ways of television politics in California might assume this is an attack on a proposed tax cut for the oil industry or a slap at a candidate opposed to environmental controls.

It is neither. Instead, Garner's targets are two ballot initiatives designed to change the partisan system of redistricting state and federal legislative boundaries after the 1990 census. Propositions 118 and 119 say absolutely nothing about oil or tankers or otters. But such details are irrelevant to the campaign advertiser's art, of which the Garner spot is this year's most imaginative or egregious example, depending on your point of view.

"It's the most misleading ad I have ever seen in my life," said San Mateo County Supervisor Tom Huening, a former Common Cause activist who wrote Prop 119's plan to take redistricting power away from the state legislature and give it to a commission appointed by retired judges. "It's very frustrating," said Lezlee Westine, legal counsel for Prop 118's Citizens for Legislative Ethics.

Proposition 118, the work of Marin County businessman Gary J. Flynn, would let the legislature continue to redistrict, but only with a two-thirds vote and with no power to overturn a gubernatorial veto. It also includes stricter legislative ethics rules, such as banning gifts or honoraria from special interests.

"We do see the environmental impact as having central importance," said Sierra Club California state director Michael Paparian, who opposes the initiatives and defends the Garner spot. He argued that the existing, political system of redistricting was more likely to result in election victories of lawmakers who are friendly to environmental causes.

This is not the first, nor is it likely to be the last, bitter California battle over redistricting. Many of the Prop 118 and 119 proponents are veterans of an ill-fated 1984 initiative to weaken the Democratic-led legislature's power to draw new boundary lines. That year Assembly Speaker Willie Brown (D) and his allies used actor Jack Lemmon in commercials that tarred the measure as a plot to "politicize the judiciary." Lemmon has returned this year to label Props 118 and 119 a "fraud."

This time initiative proponents are fighting back with their own vivid, and to some irrelevant, images. One of the most effective pro-119 commercials shows Brown with a smug expression. "Assembly Speaker Willie Brown had a real good laugh last time we tried to reform government," the announcer says. "He even bragged about how he conned voters with TV ads featuring Jack Lemmon." The screen shows Lemmon looking guilty as the announcer adds: "Don't you be fooled. Proposition 119 will help keep the politicians honest." Another Prop 119 spot has Charlton Heston telling fellow Academy Award winner Lemmon to "get honest."

The latest Los Angeles Times poll shows Prop 118 leading 42 to 32 percent and Prop 119 tied 37 to 37 percent, but a quarter of voters remain undecided. If both pass, the proposition with the most votes would go into effect.

Most of the passion on the pro-initiative side comes from Republicans, who are convinced the present system allows the Democratic legislature, and clever redistricting consultants like Michael Berman, to carve out more than their share of seats. Democrats hold 60 percent of the state's congressional and state Senate seats and 59 percent of its state Assembly seats, yet have just under 50 percent of registered voters and an even lower percentage of those who actually cast ballots.

Brown and other party leaders have raised more than $3.5 million to fight the initiatives. The proponents netted $1.2 million from a fund-raiser attended by President Bush, but expect to be outspent 3 to 1.

Both sides predict a close vote, although Karin Caves, spokeswoman for the "No on 118 and 119" campaign, said beating 118 will be particularly difficult because "the ethics veneer there is very attractive."

In a contest this vital to the future of both parties, all issues become fair game. One opponent suggested the initiatives would unleash more assault rifles on the streets because the National Rifle Association supports them. Initiative supporters noted that the Garner anti-oil spot is partially paid for by $10,000 from the ARCO Corp.

ARCO spokesman Al Greenstein said the oil company is neutral on the issue and gave the money last year to a fund Brown maintains for any initiative expenses he deems advisable. "We have supported Willie Brown in the past," Greenstein said, "and he has always used such contributions responsibly."