Voters in California will likely decide this November whether or not to legalize marijuana, after legalization activists handed in far more than the necessary number of petition signatures to get the measure onto the ballot.

Organizers of the Regulate, Control and Tax Cannabis Act of 2010 filed some 700,000 petition signatures with county clerks around the state. The amount of signatures needed to get the measure on the ballot is about 433,000, reports the San Francisco Chronicle, so the measure is all but certain to be on the ballot in November.

If California voters approve, it will be the most comprehensive reform of marijuana laws ever undertaken in the United States. While some states, such as Oregon, have relatively lax penalties for possession, no state has attempted to regulate and tax the herb before.

The measure's chances are good: A poll taken last April found that 56 percent of Californians want to see the herb legalized and taxed.

According to the L.A. Times, the measure would make it legal for anyone over 21 to own an ounce or less of pot, and to grow pot for personal use in a space no larger than 25 square feet. It would also give cities the right to license marijuana growers and sellers, and to collect taxes on the crop.

One of the major talking points that the pro-legalization crowd has used has been finances. California's government is facing a deep, prolonged budget crisis, and legalization proponents have argued that the revenue generated by taxing marijuana would bring an estimated $1.3 billion into state and municipal coffers.

Richard Lee, a medical marijuana entrepreneur from Oakland who is the principal backer of the movement, told the L.A. Times he plans to raise $10 million to $15 million to fight the legalization campaign. And Lee's opponents are already beginning to line up to oppose the measure.

''We're going to talk about blood money, about trying to raise taxes on the backs of our youth,'' Bishop Ron Allen, head of the International Faith Based Coalition, told the Associated Press.

Another obstacle will be the conflict between state and federal law. Even if California passes the measure, marijuana will still be illegal under federal statutes. In an editorial this month, the L.A. Times argued:

Cannabis may be the nation's largest cash crop, but marijuana remains a Schedule I drug, deemed by the federal government to have a high potential for abuse, no accepted medical value and illegal to use under all circumstances. Perhaps Californians have been emboldened by their pioneering role in legalizing medicinal marijuana, but in truth, the conflict between state and federal law has had serious consequences for users and distributors caught in the federal web.

But, in a rebuttal, Tamar Todd argued that "there is nothing in the US Constitution that requires states to criminalize anything. We could scrap our entire penal code tomorrow if we wanted to. States get to decide state law, not Washington."

And Jacob Sullum at Reason.com argues that, while the feds may still want to enforce federal marijuana laws in California, they won't have the resources to prosecute cases that were previously handled by state authorities.