Keep in mind that it's just a bill and not a law yet but this could be the first step to the state figuring out how to make some money. 

CapitolFax - The Senate bill, SB 316, is sponsored by Senate Appropriations Committee Chairwoman Heather Steans (D-Chicago).... would make it legal for adults 21 and older to possess, grow, and purchase limited amounts of marijuana. The state would license and regulate businesses to cultivate, process, test, and sell marijuana to adults, and it would create and enforce strict health and safety regulations, such as testing and labeling requrements and restrictions on marketing.

The bill proposes to tax marijuana at a rate of $50 per ounce at the wholesale level, and it would be subjected to the retail tax of 6.25%. These rates are based on the market price currently being used in Colorado, where weed has been legal since January 2014. The Marijuana Policy Project estimates that regulated sales of marijuana sales could generate between $350 and $700 million dollars a year.

That's a good chunk of change. While it's not even 10% of Illinois' current deficit of almost $10 billion, it's a start.  It will not eliminate illegal drug transactions between civilians, but it will put a deep cut in their business, which will hopefully in turn end the parade of people going to our prison system for marijuana crimes.

The legalization of marijuana has grown rapidly in acceptance over the past few years.

A February Quinnipiac poll found 59% of U.S. voters think marijuana should be made legal... People are fed up with laws that punish adults for using a substance that is far less harmful than alcohol.

The last sentence is what should drive this bill to a law. The time where alcohol is not only legal but openly advertised and marijuana possession is a criminal offense will be over soon, just a question of how soon.