It’s official. Tax Cannabis 2010, the most far-reaching state effort ever, which would legalize the consumption of cannabis for all adults over 21 — and would finally take the industry that serves those consumers out of a legal gray area — will qualify for the November mid-term ballot later today.

The Tax Cannabis campaign gathered just under 700,000 signatures, well over the 434,000 needed to qualify for the California ballot.

For background on the initiative, read my extensive analysis of the campaign, spearheaded by Richard Lee, the pot entrepreneur behind Oaksterdam University in Oakland.

From that article, here’s a primer on what this measure would change, if it were to pass:

The measure does not actually legalize pot as much as it absolutely decriminalizes certain marijuana offenses. (Marijuana has been “decriminalized” in California since 1975, but it still can generate a fine, an arrest and a misdemeanor charge on your record.) Tax Cannabis institutes a one-ounce personal possession limit and allows for limited personal cultivation.

Interestingly, the ballot initiative refers to local control, meaning that cities and counties can decide whether to allow regulated marijuana sales at all, and if so, how that would work. Tax Cannabis allows for the personal consumption, possession and cultivation of cannabis by any adult over 21 throughout the state, but the business of it would be left to local jurisdictions. (A few people suggested Lee was inspired by his home state of Texas’ dry-county, wet-county policy regarding alcohol sales.)

Polling shows that a growing number of people here in California think legalization is the right solution to this particular segment of the drug war. A poll in April showed 56 percent support for legalization. And Tax Cannabis’ internal polling in March found 44 percent support among likely California voters in non-presidential elections. This was followed by an August internal poll that found 52 percent support by likely November 2010 voters.

These slim majorities are not ideal, but that’s why Tax Cannabis is focused on a public-education campaign, and will be targeting their message to fit the different concerns and needs of all kinds of voters across the state.

I still stand behind what I wrote back in January: This is the best chance for marijuana legalization on a state-level yet. And as 13 states have followed California in legalizing medical marijuana, other states could similarly follow it if legalizes cannabis this year. In other words, as goes California, so could go many others.