As if there weren't enough to stir the emotions in the Bush-Kerry presidential contest, Election Day will offer voters in more than 30 states an opportunity to vent their feelings on a variety of social and legal issues, from same-sex marriage to bear baiting to caps on medical malpractice awards.

California, where the voter initiative has become a favorite tool for governing, offers a menu of 16 issues -- including a $3 billion stem cell research program and a narrowing of the state's famous "three strikes" law, which mandates life sentences after the third criminal conviction. Another California measure would overhaul the state's primary process, eliminating party registration for voters and allowing the top two candidates, regardless of party, to compete in November, while a fourth would repeal the precedent-setting year-old law mandating health insurance coverage by all but the smallest companies.

Analysts on both sides speculate that, of the more than 150 ballot measures up for a vote Nov. 2, the marriage and gambling initiatives and some of the health care fights may boost turnout in states, but there is little agreement on an overall partisan effect. While few initiative campaign ads are on the air as yet, it is expected that millions will be spent on them.

Eleven states have responded to the Massachusetts Supreme Judicial Court decision allowing same-sex marriage by proposing to alter their constitutions or statutes to require that the partners be one man and one woman. Missouri voters approved such a measure on the August primary ballot by a 71 percent majority. Sponsors are hoping for similar results in Arkansas, Georgia, Kentucky, Michigan, Mississippi, Montana, North Dakota, Oklahoma, Utah and Oregon -- with a petition drive pending in Ohio and a vote today in Louisiana.

Kristie Rutherford, director of state and local affairs for the Family Research Council, said collecting signatures for these initiatives has been easy. "We had very little time in most of these states and they all did it in record time and with record numbers of signatures." Gay rights and civil liberties groups are challenging in courts in Arkansas and Oklahoma and are mounting a major grass-roots effort in Oregon, believing that state may offer the best chance of defeating the measure.

"We're seeing a resurgence of social issues this year," said M. Dane Waters, founder of the Initiative & Referendum Institute. "They are fodder for election campaigns."

The overall number of ballot measures is down slightly from 2002, but, as in the past, some measures are expected to draw heavy spending. John G. Matsusaka, president of the Initiative & Referendum Institute, said the number of initiatives qualified by signature-gathering firms -- 51 -- is almost unchanged from 2002 but legislatures sent fewer measures to the voters for decision this year than in the last cycle.

"Some states have made the initiative process more cumbersome," he said, "and that may explain a decline from the 1996 peak of 93 voter-inspired initiatives." Those numbers could change slightly before November, depending on court challenges.

Still, major changes with national implications are possible. Colorado voters will be asked to decide whether the state's nine electoral votes should be apportioned according to the popular vote each candidate wins, rather than the top vote-getter receiving all nine. The change could make the difference in the electoral college outcome on Nov. 2.

In the past, gambling measures have pulled out some of the biggest checks, thanks to the potential profits for those seeking or defending these franchises. Oklahoma voters will decide whether to launch a state lottery. The measure, backed by Gov. Brad Henry (D), is expected to pump $150 million a year into the schools, with additional funds coming if voters approve a measure for state regulation and revenue sharing at the 80 Indian casinos.

In California, gambling interests are warring with each other. One measure would grant the Agua Caliente Band of Mission Indians a 99-year license and the right to expand its casino, in return for a payment of state taxes on its profits. A rival measure, backed by the state's card clubs and gambling industry, would levy a higher tax on Indian slot machines and put them under stricter state regulation.

In Michigan, a coalition of tribes and Detroit casinos is behind a "Let Voters Decide" constitutional amendment that would require a statewide vote before any new non-Indian gambling facility could open. It is aimed at heading off legislation to permit racetracks to install slot machines. In Nebraska, a series of proposed changes would open the state -- or individual cities -- to casino gambling.

As is often the case, animal rights, health measures, tobacco, anti-crime campaigns and taxes have spawned many issues. Alaskans, for example, will vote on a proposed ban on setting out food to attract bears as targets for hunters.

Trial lawyers and medical providers are squaring off over limits on malpractice suits and awards in Florida, Nevada, Oregon and Wyoming. The measures, backed by medical groups, would either limit damages and lawyers' fees or set tougher conditions for bringing such cases into court. On the other side, two Florida initiatives would open doctors' records to more scrutiny and bar from practice any physician found to have committed three cases of malpractice. As with the gambling measures, the economic stakes in these fights guarantee heavy spending on both sides.

Environmentalists and developers are battling over public land swaps in Arizona, the use of cyanide in gold mining in Montana and land use in Oregon. Tax limitation measures are on the ballot in Indiana, Maine and South Dakota.

The Washington state teachers union is trying to overturn a new charter schools law, arguing that despite widespread acceptance in other states they would harm public education. In Nevada, a ballot measure would require annual per-pupil spending to at least equal the national average.

Organized labor and its friends are pushing an initiative to raise the minimum wage in Florida and Nevada.

Florida Gov. Jeb Bush (R) is involved in trying to defeat a referendum that would overturn legislation requiring parental notification if a minor seeks an abortion.

A practice unique to South Carolina -- a long-standing requirement that bars and restaurants serve liquor from shot-size mini-bottles -- is being challenged on the ballot, providing diversion for customers of both kinds of establishments.

An effort to decriminalize the use of marijuana failed to make the ballot in Nevada, but a similar measure will be up for a vote in Alaska, and Montana voters will consider allowing medical use of marijuana.

In Arizona, a proposed initiative would require people applying to vote to submit evidence of U.S. citizenship and require officials to report to federal immigration officials anyone seeking state benefits who lacks such proof.

Colorado, Montana and Oklahoma are considering initiatives that would raise tobacco taxes and earmark the proceeds for health programs. Colorado will vote on a 64-cent-a-pack boost, Oklahoma a 55-cent increase and Montana a $1 rise.

California's ballot includes measures to increase emergency medical services, financed by a telephone surcharge, and to expand mental health programs, with a surtax on incomes of more than $1 million..

But probably the biggest health care fight is another California proposition that would repeal legislation signed by then-Gov. Gray Davis (D) to require all employers of at least 20 people to provide medical insurance, with the company paying at least 80 percent of the cost. The employer mandate, hailed last year by labor and liberals as a great victory, is blamed by business for putting a competitive burden on California companies, and the two sides are lined up for a pitched battle. Many of the same California business groups are backing a measure to tighten the rules on lawsuits claiming injury from unfair business practices.

The initiative process itself is on the ballot. The Arizona legislature, reacting to a surge in voter initiatives, has placed on the ballot measures that would advance the deadline for filing signatures by three months as well as other restrictions. Florida, too, will consider moving up the deadline for qualifying initiatives, in this case to January of each election year.

The same objective -- making the process harder -- is being sought by an Alaska referendum that would require petitioners to collect signatures from more areas of the state. On the other hand, a Nebraska initiative would require a two-thirds vote in the unicameral legislature to repeal or amend a law enacted by initiative.

Term limits, imposed by initiative in many states in the past decade, are coming under review. The Arkansas legislature wants voters to increase the maximum period of service in the state House from six to 12 years and in the state Senate from eight to 12 years.

Alaskan voters will decide whether to strip their governor of the power to make temporary appointments to fill a U.S. Senate vacancy -- an emotional issue there after Gov. Frank H. Murkowski (R), who quit the chamber to become the state's chief executive and named his daughter Lisa as his replacement.

Political researcher Brian Faler contributed to this report.