American tobacco giants, facing state ballot measures that would sharply increase excise taxes or expand smoking bans, are fighting back. They are spending tens of millions of dollars and, in some cases, pushing rival propositions that sound like tough restrictions but would actually ease antismoking laws already on the books.

The campaign drawing most of Big Tobacco's attention is in California, where Reynolds American Inc. and Philip Morris USA, along with parent Altria Group Inc., have already sunk a combined $55 million into a drive to oppose increasing taxes on a pack of smokes by $2.60. The measure, on the November ballot, would generate an estimated $2.1 billion in annual revenue for the state and make California's tobacco excise tax, currently at 87 cents a pack, the highest in the nation. Proceeds from the tax would be used to finance health programs, primarily for children.

The companies are spending so heavily there because the stakes are so high. Philip Morris, the industry's largest cigarette maker, says that California is its single-largest domestic market. Reynolds, the nation's No. 2 tobacco company, says the state accounts for about 6 percent of its cigarette sales. "Clearly, the impact of California would put pressure on earnings," said Dianne Neal, Reynolds's chief financial officer, during an analyst conference in late July. During the same conference, Ms. Neal said that, altogether, the company planned to spend $40 million to defeat tax increases and smoking bans on state ballots around the country this November.

A leader in citizen-driven proposition balloting, California has often seen pricey campaigns by big businesses seeking to defeat hostile ballot initiatives, and this year is no exception. Another measure, to raise taxes on oil, has sparked an expensive campaign by oil companies. In 2005, a group of pharmaceutical companies spent $73 million to defeat a proposed prescription-drug discount plan. And in 1998, insurance companies spent $66 million to defeat an auto-insurance measure. "Initiative campaigns are not cheap -- this is not an inexpensive venture," said Reynolds spokesman David Howard.

So far, the coalition of cigarette companies and snuff and cigar manufacturers has outspent proponents of this year's cigarette-tax proposal -- mostly a collection of California hospitals -- by a 3-to-1 margin. State records show that, a month before the election, Philip Morris had put $30.7 million into the campaign and Reynolds had donated nearly $24 million. As of the end of September, the antitax campaign had already spent more than $48 million.

The result has been a tidal wave of television advertising attacking the tax increase and its main backer, a California hospital association, whose members stand to benefit most from the new tax. "I was in California two days last week, and that's all I saw on TV," said Kristina Wilfore, executive director of the left-leaning Ballot Initiative Strategy Center. "They were even airing it on the Cartoon Network at midnight."

Beyond California, the companies are fighting similar tax measures in Missouri, Arizona, South Dakota and Ohio. In Missouri, the state's supreme court is considering whether to allow an 80-cent-a-pack tax increase to appear on the November ballot, over a legal challenge. If the measure survives, Mr. Howard said, "it's safe to say" the company will wage a multimillion-dollar campaign to defeat it.

Philip Morris spokeswoman Peggy Roberts said the company has begun consumer and vendor campaigns to defeat a proposed $1-a-pack tax increase in South Dakota and an 80-cent-a-pack increase in Arizona. She said the company was mounting a similar effort in Cuyahoga County, Ohio, where voters will be asked to approve a 30-cent-a-pack tax on cigarettes to finance a local arts program.

Ms. Roberts declined to say how much the company was spending on the campaigns.

The ferocity that Big Tobacco has shown this year in opposing the cigarette taxes contrasts with the industry's relative inactivity on the issue in recent years. The two cigarette companies offered only token resistance to a 2002 proposal in Missouri to raise cigarette taxes 55 cents. They spent a combined $77,000 defeating the proposal, state records show, even as a group of health charities and others spent more than $5 million pushing the effort. That same year, a 60-cent tax increase proposed in Arizona passed with no money being spent by opponents, according to state records. In Florida in 2002, Philip Morris abruptly ended a drive to counter a smoking ban with a softer measure after spending $360,000 on a petition drive.

Political observers say they haven't seen tobacco interests spend so much money on a statewide proposition since 1994, when a cigarette-tax increase went down in defeat in Colorado after an $8 million campaign against it -- a sum that remains a record in that state.

Company spokesmen declined to discuss their reasons for increasing their political activities this year beyond saying that business considerations govern their decisions to enter the political fray.

Dan Smith, a University of Florida political-science professor who studies ballot issues, said the sheer number of proposals may have convinced the companies they need to counter the mushrooming antismoking activism that has taken over statehouses in recent years. Some 41 states have passed cigarette-tax increases in the past five years. A host of others have banned smoking in many public places.

"In the last political round, the tobacco giants basically conceded the issue," Mr. Smith said. "I think they've decided to make a last stand. These proposals are going to keep coming if they're not knocked down."

While Philip Morris has focused its efforts on taxes, Reynolds has mounted a sturdy resistance to proposed smoking limits in Ohio and Arizona this year. Both states are entertaining proposals to virtually eliminate smoking in public buildings.

Reynolds is bankrolling proposals in both states that critics say are designed to confuse voters. In Ohio, voters will be asked to consider two smoking-related measures. One, called SmokeFreeOhio, would change state statutes to ban smoking in most buildings other than private homes and a certain percentage of hotel rooms. It is supported by health charities such as the American Cancer Society.

A rival proposal on the ballot, backed by a group called Smoke Less Ohio, also purports to restrict smoking, through a constitutional amendment. But this proposal would exempt restaurants, bars, bowling alleys and similar establishments. If passed, it would actually unwind more restrictive existing municipal bans. It is being supported by a coalition of bars and restaurants, local retail outlets, Loews Corp.'s Lorillard Tobacco Co. and Reynolds.

Mr. Howard, the Reynolds spokesman, said his company supports the constitutional measure and is prepared to bankroll a multimillion-dollar campaign to see it passed. "We believe this is a way you can still provide a smoker-friendly environment for people who choose to smoke," he said.

Jacob Evans, a spokesman for Smoke Less Ohio, declined to say how much money Reynolds was providing for the campaign but acknowledged that the company was "our main supporter." State campaign-finance documents show Smoke Less Ohio spent $1.5 million through Aug. 9 gathering signatures to place it on the ballot.

Recent polling shows about 45 percent of the state's voters support the Reynolds-backed measure. Polling shows 58 percent support for the ban endorsed by the health groups. Both measures require simple-majority support to succeed. But if both pass, the Reynolds-sponsored measure would prevail.

Tracy Sabetta, of SmokeFreeOhio, admitted her group may have been politically outmaneuvered when it decided to pursue its measure as a statutory change in state law rather than a constitutional amendment. "We could get 90 percent of the vote and theirs could still trump ours," she said.

In Arizona, Reynolds has adopted a similar strategy of backing a rival to the proposed smoking ban. There, state records show, Reynolds had by mid-August funneled nearly $3 million to a local group called the Non-Smoker Protection Committee, which is backing Proposition 206. Though ostensibly a smoking ban, it would actually unwind existing prohibitions in Tempe and other cities by exempting bars and restaurants statewide. A rival proposal, Proposition 201, which is supported by several health charities, provides no such exceptions.

In Arizona, the smoking measure with the most votes will become law. Recent polling showed the Reynolds-backed proposal had slightly more support than the one backed by the health charities.

Dueling smoking bans will also appear on the ballot in Nevada this year, but campaign-finance records suggest that tobacco companies have left that battle to convenience stores and liquor and gambling interests.

Mr. Smith, the political-science professor, said Reynolds's tactics in Ohio and Arizona are similar to those used by insurance companies to defeat the 1998 California auto-insurance measure. They clotted the ballot with five competing ballot questions on the subject. "Counterproposals confuse voters, and when voters are confused, they vote 'No,'" Mr. Smith said. "That's just the default position."